Quality Control Profiles - Elecard Boro VoD

Number of video tracks

Reset to default

Specify the number of video tracks in the file and save the form to apply the settings to the template.
The default number of video tracks is 1.
The system allows you to create a template for checking a file with several tracks. After saving the form, the system will allow you to specify individual values in tests for each video track.

Number of audio tracks

Reset to default

Specify the number of audio tracks in the file and save the form to apply the settings to the template.
The default number of audio tracks is 1.
The system allows you to create a template for checking a file with several tracks. After saving the form, the system will allow you to specify individual values in tests for each audio track.

Thumbnails

Reset to default

Interval

s

Freeze interval

s

Thumbnail quality

%

The probe captures thumbnails and sends them to the server with a specified interval.
Interval is an integer value that specifies an interval between thumbnail captures in seconds. Setting the value to 0 disables thumbnail capturing. The default value is 10 seconds.
Freeze interval is an integer value that specifies an interval between thumbnail captures in seconds during a video freeze. Setting the value to 0 disables thumbnail capturing. The default value is 10 seconds.
Thumbnail quality is an integer value that specifies thumbnail compression quality within the interval from 30 to 100. The default value is 70.

File size

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Severity level:

Minimum

Maximum

Checks that the file size matches the specified threshold values:
If only a minimum value is set, then it is checked that the file size is not below this value;
If only a maximum value is set, then it is checked that the file size doesn't exceed this value;
When both values are provided, it is checked that the file size is within the range between the minimum and maximum values inclusively.
You can use bytes, kilobytes, megabytes, and gigabytes as units of measurement.

Container format

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Severity level:

MP4

Stop if condition not met

Checks that the container format matches formats indicated in the template.
The default value is MP4.
When the Stop if condition not met option is enabled, the system will stop the file analysis if template values are not matched.
A container is a file format. Containers can comprise video and audio tracks, subtitles, service information, and metadata.
Container examples: MPEG-1 System Stream, MPEG-2 Program Stream, MPEG-2 Transport Stream, MP4, MOV, MKV, WebM, AVI, FLV, IVF, MXF, etc.

File extension

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Severity level:

Comma-separated list

Checks that the file extension matches the values in the template.
The default values include mp4, mov.
File name extension is a sequence of characters for file type identification.
Though the extension doesn't guarantee belonging to a certain container format, a file with a wrong extension in the name may be ignored in the production chain. To determine the container format precisely, use the Container format test.

Video format

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Severity level:

MPEG-1

MPEG-2

AVC/H.264

HEVC/H.265

Stop if condition not met

Checks that the video format matches the values in the template.
The default value is AVC/H.264.
When the Stop if condition not met option is enabled, the system will stop the file analysis if template values are not matched.

Audio format

Reset to default

Severity level:

MPEG Audio

AAC

Stop if condition not met

Checks that the audio format matches the values in the template.
The default value is AAC.
When the Stop if condition not met option is enabled, the system will stop the file analysis if template values are not matched.

Number of audio and video tracks

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Severity level:

Checks that the number of audio and video tracks in the container matches the values in the settings of the template.
The default values are 1, 1.

Audio and video start timestamp

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Severity level:

Start timestamp (hh:mm:ss.ms)

Checks that the start timestamp of audio and video tracks matches the threshold value indicated as hh:mm:ss.ms in the template.
The default value is 00:00:00.000
A start timestamp is usually equal to 0. A wrong start timestamp value will result in the file time shift and will possibly lead to difficulties with positioning this file in the player when playing it.
The Audio and video start timestamp and Audio and video end timestamp tests are used to identify the duration of audio and video tracks in the file by means of timestamps. The duration identified in such a way is used for cross-testing in the Audio and video duration mismatch test.

Audio and video end timestamp

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End timestamp (hh:mm:ss.ms)

Checks that the end timestamp of audio and video tracks matches the threshold value indicated as hh:mm:ss.ms in the template.
The Audio and video start timestamp and Audio and video end timestamp tests are used to identify the duration of the file by means of timestamps. The duration identified in such a way is used for cross-testing in the Audio and video duration mismatch test.

Audio duration

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Severity level:

Minimum

Maximum

Checks that the audio duration matches the specified threshold values indicated as hh:mm:ss.ms in the template.
If only a minimum value is set, then it is checked that the audio duration is not below this value;
If only a maximum value is set, then it is checked that the audio duration doesn't exceed this value;
When both values are provided, it is checked that the audio duration is within the range between the minimum and maximum values inclusively.

Video duration

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Severity level:

Minimum

Maximum

Checks that the video duration matches the specified threshold values indicated as hh:mm:ss.ms in the template.
If only a minimum value is set, then it is checked that the video duration is not below this value;
If only a maximum value is set, then it is checked that the video duration doesn't exceed this value;
When both values are provided, it is checked that the video duration is within the range between the minimum and maximum values inclusively.

Audio and video duration mismatch

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Severity level:

Acceptable discrepancy threshold

ms

Compares the duration of all audio and video tracks in the container.
The allowed discrepancy threshold is indicated in milliseconds.
The default value is 300 ms.

Absence of mandatory MP4 boxes

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Severity level:

Checks the presence of mandatory box elements in an MP4 container: ftyp, mdat, moov, mvhd.
We strongly recommend you to activate this test in the template when checking MP4 containers. Missing mandatory box elements or errors in their structure can make it impossible to analyze or open such a file.

Duration of MP4 container

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Severity level:

Acceptable discrepancy threshold

ms

Checks that the value of the duration parameter from the Media Header Box (mdhd) in an MP4 container matches the actual duration of audio and video tracks calculated by means of timestamps.
The allowed discrepancy threshold is indicated in milliseconds in the template.
The default value is 300 ms.
The specified duration of an MP4 file may not match the actual one. It is assumed that the actual duration is the one calculated by means of timestamps.

Timescale in mvhd box

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Severity level:

Checks the presence of the timescale value in the Movie Header Box (mvhd) of an MP4 container. It also checks that the value is not equal to 0. The timescale value is used to calculate the duration of video frames and audio samples in an MP4 container.

Video timestamp discontinuity

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Severity level:

Threshold

ms

Checks the continuity of timestamps in video tracks of an MP4 container. It analyzes the absolute difference between video timestamp values and outputs an error if the threshold value is exceeded.
The default value is 100 ms.

Audio timestamp discontinuity

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Severity level:

Threshold

ms

Checks the continuity of timestamps in audio tracks of an MP4 container. It analyzes the absolute difference between audio timestamp values and outputs an error if the threshold value is exceeded.
The default value is 100 ms.

Container and elementary metadata mismatch

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Severity level:

Compares the key headers in the configuration of audio and video tracks at the level of the container and the level of elementary streams.
The following headers are checked:

for audio tracks: format, sampling rate, profile, number of channels;
for video tracks: format, profile, level, resolution, chroma subsampling, bit depth, maximum number of reference frames, scanning type. If present, the aspect ratio, the frame rate, the colorimetric parameters are also checked.

This metadata is required for the correct decoder initialization. Usually, the elementary level data is used, but it all depends on the actual player implementation. That is why it is important to keep metadata identical.

Video resolution

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Severity level:

track 1
7680 x 4320 (8K) 3840 x 2160 (4K) 2560 x 1440 (2K) 1920 x 1080 (Full HD) 1280 x 720 (HD) 960 x 540 (SD) 854 x 480 (SD) 720 x 576 (SD) 640 x 360 (SD) 426 х 240 (SD)

Checks that the video resolution indicated in the header of elementary video tracks matches the values in the template.
The default value is 1920x1080.
Video resolution is the number of pixels measured both vertically and horizontally.
The following values are checked:

the MPEG-1 and MPEG-2 video formats: the horizontal_size_value and vertical_size_value in the Sequence Header;
the MPEG-4 part 10 AVC/H.264 video format: the pic_width_in_mbs_minus1 and pic_height_in_map_units_minus1 values in the Sequence Parameter Set header;
the MPEG-H part 2 HEVC/H.265 video format: the pic_width_in_luma_samples and pic_height_in_luma_samples values in the Sequence Parameter Set header.

Video resolution changed

Reset to default

Severity level:

Detects a change of video resolution in the headers of elementary video tracks.
A change in video resolution may result in the player decoder or transcoder crash or reinitialization with service interruption.

Video profile and level

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Severity level:

track 1
For MPEG2 Profile Level For AVC/H.264 Profile Level For HEVC/H.265 Profile Level

Checks that the Profile and Level values in the headers of video tracks match the values in the template.
Profile is a parameter responsible for the subset of the available encoder and decoder syntax. In other words, Profile indicates a set of methods available for encoding and required for decoding. For example, the Baseline Profile in the AVC/H.264 video format doesn't let you use CABAC entropy coding, encode B frames and video with Bit Depth equal to 10 bits.
Level is a set of limitations imposed on the values of syntax elements, for example, the size of frames and blocks, the size of the video buffer, etc. The Level value is set depending on the video resolution. The lower the value, the more limitations are applied.

For the MPEG-2 video format, the profile_and_level_indication value (Table 8-2, Table 8-3) in the Sequence Extension header is checked.

For the AVC/H.264 video format, the profile_idc and level_idc values in the Sequence Parameter Set header are checked. To identify Profile accurately, the constraint_set[N]_flag value is also used.
Common Level values: 1–2 are applicable to the resolution up to 352х288 pixels, 2–3 are for up to 720х576 pixels, 3–4 are for up to 2048х1024 pixels, 4–5 are for up to 3680х1536 pixels, 5–5.2 are for up to 8192х4320 pixels.

For the HEVC/H.265 video format, the general_profile_idc and general_level_idc values in the Sequence Parameter Set header are checked.

Video profile and level changed

Reset to default

Severity level:

Detects changes of Profile and Level values in the headers of elementary video tracks. Changes in Profile and Level values result in changes of video syntax and can lead to the player decoder or transcoder crash or reinitialization with service interruption.

Chroma subsampling

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Severity level:

track 1
4:4:4 4:2:2 4:2:0

Checks that the chroma subsampling value in the headers of video tracks matches the value in the template.
The default value is 4:2:0.
Digital images are made of pixels. In digital television, the color of each pixel is formed according to the YUV model, where Y is a luminance component, and Cr and Cb are two chrominance components. The chroma subsampling technology implies saving Y component data for each pixel, while Cr and Cb color data is saved only for pixel groups. This means Cr and Сb components are transmitted with reduced resolution. This is because the human eye is less susceptible to changes in color than luminance. There are the following subsampling formats:

4:4:4 means Cb and Cr components are transmitted with full resolution;
4:2:2 means Cb and Cr components have the same resolution with Y luminance component vertically and only half of the Y resolution horizontally. This format is often used in studios for video editing or can be found in master files. It’s pretty much never used in content delivery to end users;
4:2:0 means Cb and Cr components have half of Y resolution both vertically and horizontally. It is the most common format in digital television. End users receive content in this exact format.
other.

Checked values:

the MPEG-2 video format: the chroma_format value in the Sequence Extension header;
the AVC/H.264 and HEVC/H.265 video formats: the chroma_format_idc value in the Sequence Parameter Set header.

Chroma subsampling changed

Reset to default

Severity level:

Detects changes of chroma subsampling values in the headers of elementary video tracks.
A change in chroma subsampling leads to a change in video and may result in the player decoder or transcoder crash or reinitialization with service interruption.

Scan type

Reset to default

Severity level:

track 1
Interlaced Progressive

Checks that the scan type in the headers of video tracks matches the template value.
The default value is the progressive scan type.
There are two scan types used in television:

interlaced scan is a technology developed for analog television when each frame is split into two fields made of lines. The first field comprises odd-numbered lines, and the second one — even-numbered lines. The industry is gradually moving from the interlaced video to a progressive one;
progressive scan is a technology when all lines are displayed sequentially.

Interlaced scan pretty much isn’t used in streaming services and OTT platforms.
UHD 4K television doesn’t rely on interlaced scan at all.

Checked values:

the MPEG-2 video format: the progressive_sequence value in the Sequence Extension header and the progressive_frame value in the Picture Coding Extension header;
the AVC/H.264 video format: the frame_mbs_only_flag and pic_struct_present_flag values in the Sequence Parameter Set header, the field_pic_flag value in the Slice Header, the pic_struct value in SEI pic.timing;
the HEVC/H.265 video format: the general_progressive_source_flag and general_interlaced_source_flag, field_seq_flag in the Sequence Parameter Set header, the pic_struct and source_scan_type values in SEI pic.timing.

Scan type changed

Reset to default

Severity level:

Detects changes of the video scan type in the headers of elementary tracks.
A change in the scan type leads to a change in video and may result in the player decoder or transcoder crash or reinitialization with service interruption.

Scan order

Reset to default

Severity level:

track 1
Top field first (TFF) Bottom field first (BFF)

Checks that the order of fields in the headers of video tracks with the interlaced scan type matches the template value.
The default value is TFF.
The field order determines which of the fields is the first one:

TFF means the upper field is the first; contains a sequence of odd-numbered lines;
BFF means the lower field is the first; contains a sequence of even-numbered lines.

Checked values:

the MPEG-2 video format: the top_field_first value in the Picture Coding Extension header;
the AVC/H.264 video format: the bottom_field_flag value in the Slice Header;
the HEVC/H.265 video format: the pic_struct value in the SEI pic.timing header.

Scan order changed

Reset to default

Severity level:

Detects changes of the order of fields in the headers of elementary video tracks with the interlaced scan type.
A change in the order of fields leads to a disruption in stream decoding and the player decoder or transcoder crash or reinitialization with service interruption.

Colorimetric parameters

Reset to default

Severity level:

track 1

Checks that colorimetric parameters in the headers of video tracks match the template values.

Default value sets:

Unspecified: 2, 2, 2;
SDR (Standard Dynamic Range), recommended by ITU-R BT.709-6: 1,1,1;
HDR (High Dynamic Range), recommended by ITU-R BT.2020-2 and Rec. ITU-R BT.2100-2: 9,16,9 (for HDR10, HDR10+, Dolby Vision), 9,18,9 (for HLG, Dolby Vision).

Checked values:

Colour primaries value indicates the coordinates of main chrominance components according to the CIE 1931 (ISO 11664-1) system.

The value	for MPEG-2 (ISO/IEC 13818-2 : 2000 (E), Tables 6-7)	AVC/H.264 (Rec. ITU-T H.264 (08/2021), Table Е-3)	HEVC/H.265 (Rec. ITU-T H.265 (V9) (09/2023), Table E-3)
0	Forbidden	Reserved	Reserved
1	ITU-R BT.709	ITU-R BT.709-6 ITU-R BT.1361-0	ITU-R BT.709-6 ITU-R BT.1361-0
2	Unspecified	Unspecified	Unspecified
3	Reserved	Reserved	Reserved
4	ITU-R BT.470-2 System M	ITU-R BT.470-7 System M	ITU-R BT.470-6 System M
5	ITU-R BT.470-2 System B, G	ITU-R BT.470-7 System B, G ITU-R BT.601-7 625 ITU-R BT.1358-0 625 ITU-R BT.1700-0 625	ITU-R BT.470-6 System B, G ITU-R BT.601-7 625 ITU-R BT.1358-0 625 ITU-R BT.1700-0 625
6	SMPTE 170M	ITU-R BT.601-7 ITU-R BT.1358-1 ITU-R BT.1700-0 SMPTE ST 170	ITU-R BT.601-7 ITU-R BT.1358-1 ITU-R BT.1700-0 SMPTE ST 170
7	SMPTE 240M	SMPTE 240M	SMPTE ST 240
8	Reserved	Generic film	Generic film
9		ITU-R BT.2020-2 ITU-R BT.2100-2	ITU-R BT.2020-2 ITU-R BT.2100-2
10		SMPTE ST 428-1	SMPTE ST 428-1
11		SMPTE RP 431-2 SMPTE RP ST 2113	SMPTE RP 431-2 SMPTE ST 2113
12		SMPTE EG 432-1 SMPTE ST 2113	SMPTE EG 432-1 SMPTE ST 2113
13-21		Reserved	Reserved
22		EBU Tech. 3213-E	EBU Tech. 3213-E
23-255		Reserved	Reserved

Transfer characteristics value indicates reference electrooptical transfer characteristics of the source image.

The value	for MPEG-2 (ISO/IEC 13818-2 : 2000 (E), Tables 6-8)	AVC/H.264 (Rec. ITU-T H.264 (08/2021), Tables Е-4)	HEVC/H.265 (Rec. ITU-T H.265 (V9) (09/2023), Table E-4)
0	Forbidden	Reserved	Reserved
1	ITU-R BT.709	ITU-R BT.709-6 ITU-R BT.1361-0	ITU-R BT.709-6 ITU-R BT.1361-0
2	Unspecified	Unspecified	Unspecified
3	Reserved	Reserved	Reserved
4	ITU-R BT.470-2 System M	ITU-R BT.470-7 System M ITU-R BT.1700-0	ITU-R BT.470-6 System M
5	ITU-R BT.470-2 System B, G	ITU-R BT.470-7	ITU-R BT.470-6 System B, G TU-R BT.1700-0
6	SMPTE 170M	ITU-R BT.601-7 ITU-R BT.1358-1 ITU-R BT.1700-0	ITU-R BT.601-7 ITU-R BT.1358-1 ITU-R BT.1700-0 SMPTE ST 170
7	SMPTE 240M	SMPTE 240M	SMPTE ST 240
8	Linear transfer characteristics	Linear transfer characteristics	Linear transfer characteristics
9	Reserved	Logarithmic transfer characteristic (100:1 range)	Logarithmic transfer characteristic (100:1 range)
10		Logarithmic transfer characteristic (100 * Sqrt( 10 ) : 1 range)	Logarithmic transfer characteristic (100 * Sqrt( 10 ) : 1 range)
11		IEC 61966-2-4	IEC 61966-2-4
12		ITU-R BT.1361-0	ITU-R BT.1361-0
13		IEC 61966-2-1 sRGB IEC 61966-2-1	IEC 61966-2-1 IEC 61966-2-1
14		ITU-R BT.2020-2	ITU-R BT.2020-2
15		ITU-R BT.2020-2	ITU-R BT.2020-2
16		ITU-R BT.2100-2 SMPTE ST 2084	ITU-R BT.2100-2 SMPTE ST 2084
17		SMPTE ST 428-1	SMPTE ST 428-1
18		ARIB STD-B67 ITU-R BT.2100-2	ARIB STD-B67 ITU-R BT.2100-2
19-255		Reserved	Reserved

Matrix coeffs value describes matrix coefficients used when getting luminance and chrominance signals from the green, blue and red primaries or key Y, Z and X primaries.

The value	for MPEG-2 (ISO/IEC 13818-2 : 2000 (E), Tables 6-9)	AVC/H.264 (Rec. ITU-T H.264 (08/2021), Tables Е-5)	HEVC/H.265 (Rec. ITU-T H.265 (V9) (09/2023), Table E-5)
0	Forbidden	IEC 61966-2-1 SMPTE ST 428-1	IEC 61966-2-1 SMPTE ST 428-1
1	ITU-R BT.709	ITU-R BT.709-6 ITU-R BT.1361-0 IEC 61966-2-4 SMPTE RP 177	ITU-R BT.709-6 ITU-R BT.1361-0 IEC 61966-2-4 SMPTE RP 177
2	Unspecified	Unspecified	Unspecified
3	Reserved	Reserved	Reserved
4	FCC	United States FCC Title 47 Code of Federal Regulations 73.682 (a) (20)	FCC Title 47 Code of Federal Regulations 73.682 (a) (20)
5	ITU-R BT.470-2 System B, G	ITU-R BT.470-7 System B, G ITU-R BT.601-7 ITU-R BT.1358-0 ITU-R BT.1700-0 IEC 61966-2-1 IEC 61966-2-4	ITU-R BT.470-6 System B, G ITU-R BT.601-7 ITU-R BT.1358-0 ITU-R BT.1700-0 IEC 61966-2-1 IEC 61966-2-4
6	SMPTE 170M	ITU-R BT.601-7 ITU-R BT.1358-1 ITU-R BT.1700-0 SMPTE 170M	ITU-R BT.601-7 ITU-R BT.1358-1 ITU-R BT.1700-0 SMPTE ST 170
7	SMPTE 240M	SMPTE 240M	SMPTE ST 240
8	Reserved	Indicated in equations E34-E-48	Indicated in equations E34-E-48
9		ITU-R BT.2020-2 ITU-R BT.2100-2	ITU-R BT.2020-2 ITU-R BT.2100-2
10		ITU-R BT.2020-2	ITU-R BT.2020-2
11		SMPTE ST 2085	SMPTE ST 2085
12		Chromaticity-derived non-constant luminance system	Chromaticity-derived non-constant luminance system
13		Chromaticity-derived constant luminance system	Chromaticity-derived constant luminance system
14		ITU-R BT.2100-2	ITU-R BT.2100-2
15-255		Reserved	Reserved

In the MPEG-2 video format, the colour_primaries, transfer_characteristics, matrix_coefficients values in the Sequence display extension header are checked.
In the AVC/H.264 and HEVC/H.265 video formats, the colour_primaries, transfer_characteristics and matrix_coeffs values in the Sequence Parameter Set header are checked. If parameters are not defined, their values are set to 2 (unspecified). The parameters are used by displays for correct color rendition.

Colorimetric parameters changed

Reset to default

Severity level:

Detects changes of colorimetric parameter values in the headers of elementary video tracks.
A change in values will lead to a change in colour rendition on the output device, and the viewer will most likely notice it.

Display aspect ratio

Reset to default

Severity level:

track 1
16:9 5:4 4:3

Checks that the value of display aspect ratio (DAR) in the headers of video tracks matches the values in the template.
The default value is 16:9
DAR = PARхSAR
DAR (display aspect ratio) is the ratio of frame sides, which determines the way the player outputs the frame on the screen.
PAR (picture aspect ratio) is the video resolution in pixels, for example, 1920:1080, 1280:720, etc.
SAR (sample aspect ratio) is the pixel aspect ratio, for example, square 1:1.

Checked values:

the MPEG-1 and MPEG-2 video formats: the aspect_ratio_information (Table 6-3, ITU-T Rec. H.262 (2000 E)) value in the Sequence Header. If aspect_ratio_idc is missing, it is assumed the entire frame will be checked against the entire active display area;
the AVC/H.264 and HEVC/H.265 video formats: the aspect_ratio_idc, sar_width, sar_height (Table E.1, Rec. ITU-T H.265 v8 (08/2021) and Rec. ITU-T H.264 (08/2021)) values in the Sequence Parameter Set header. If aspect_ratio_idc is missing, its value is considered to be 0 (unspecified).

Display aspect ratio changed

Reset to default

Severity level:

Detects changes of the display aspect ratio (DAR) values in the headers of elementary video tracks.
A change in values will lead to a change in aspect ratio on the output device, and the viewer will most likely notice this.

Sample aspect ratio

Reset to default

Severity level:

track 1
1:1

Checks that the value of sample aspect ratio (SAR) in the headers of video tracks matches the template values.
The default value is 1:1
SAR = DAR/PAR
SAR values are used to calculate DAR, and that is why it is often enough to check DAR — Display aspect ratio.
DAR (display aspect ratio) is the ratio of frame sides, which determines the way the player outputs the frame on the screen.
PAR (picture aspect ratio) is the video resolution in pixels, for example, 1920:1080, 1280:720, etc.
SAR (sample aspect ratio) is the pixel aspect ratio, for example, square 1:1.

Checked values:

the MPEG-1 and MPEG-2 video formats: the aspect_ratio_information (Table 6-3, ITU-T Rec. H.262 (2000 E)) value in the Sequence Header. If aspect_ratio_idc is missing, it is assumed the entire frame will be compared against the entire active display area;
the AVC/H.264 and HEVC/H.265 video formats: the aspect_ratio_idc, sar_width, sar_height (Table E.1, Rec. ITU-T H.265 v8 (08/2021) and Rec. ITU-T H.264 (08/2021)) values in the Sequence Parameter Set header. If aspect_ratio_idc is missing, its value is considered to be 0 (unspecified).

Sample aspect ratio changed

Reset to default

Severity level:

Detects changes of sample aspect ratio values in the headers of elementary video tracks.
A change in values will lead to a change in aspect ratio on the output device, and the viewer will most likely notice this.

AFD codes

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Severity level:

track 1
0 2 3 4 8 9 10 11 13 14 15

Checks that the value of AFD codes in the headers of video tracks matches the template value.
Active Format Description (AFD) is a set of values passed in the headers of elementary video tracks. These values contain information about the aspect ratio and characteristics of an image. AFD (ETSI TS 101 154 Annex B, ATSC A/53 Part 4 and SMPTE 2016-1-2007) is used for TVs that support 4:3 and 16:9 aspect ratios could optimally display the picture in any format.
Value interpretation:

0	ESTI: reserved; ATSC: undefined
1	reserved
2	ETSI: 16:9 active picture (top aligned); ATSC: "not recommended"
3	ETSI: 14:9 active picture (top aligned); ATSC: "not recommended"
4	ETSI: box > 16:9 (center): wider than 16:9 active picture. The aspect ratio of the source area is not given, and the size of the top/bottom bars is not indicated. ATSC: bar data (indicating the extent of top, bottom, left, and right bars) should be transmitted when using this code.
5–7	reserved
8	Full Frame image, same as the frame (4:3 or 16:9).
9	4:3 Image: Full Frame in 4:3 frame, Pillarbox in 16:9 frame.
10	16:9 Image: Letterbox in 4:3 frame, Full Frame in 16:9 frame.
11	14:9 Pillarbox/Letterbox image.
12	unused
13	4:3 with shoot and protect 14:9 center.
14	16:9 with shoot and protect 14:9 center.
15	16:9 with shoot and protect 4:3 center.

Checked values:

the AVC/H.264 and HEVC/H.265 video formats: the active_format_flag value in the SEI user data registered itu t t35 header;
the MPEG-2 video format: the afd_data value in the user_data header.

AFD codes changed

Reset to default

Severity level:

Detects changes of AFD code values in the headers of elementary video tracks.
A change in values will lead to a change in aspect ratio on the output device, and the viewer will most likely notice this.

Frame rate

Reset to default

Severity level:

track 1
23.976 24 25 29.97 30 48 50 59.94 60

Checks that the frame rate value in the headers of video tracks matches the template value.
The default value is 25.
Frame rate is a measure of the number of frames per unit of time:

24 frames per second is a world movie industry standard;
23.976 and 59.94 are used in the American NTSC standard;
25 and 50 are used in the European PAL standard.

Checked values:

the MPEG-1 and MPEG-2 video formats: the frame_rate_code (Table 6-4, ITU-T Rec. H.262 (2000 E)) value in the Sequence Header;
the AVC/H.264 video format: the time_scale and num_units_in_tick values in the Sequence Parameter Set header;
the HEVC/H.265 video format: the vui_num_units_in_tick and vui_time_scale values in the Sequence Parameter Set header, the vps_num_units_in_tick and vps_time_scale values in the Video Parameter Set header.

Frame rate changed

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Detects changes of the frame rate in the headers of elementary video tracks.
A change in values will lead to a change in video and may result in the player decoder or transcoder reinitialization with service interruption.

Active frame rate

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track 1
frames

Determines an active frame rate using timestamps and compares it with the frame rate value from the headers of elementary video tracks. The user can set the mismatch threshold in frames.
Mismatch between the active frame rate and the one declared in headers can happen in the following cases:

A variable frame rate is indicated in headers for AVC/H.264 and HEVC/H.265.
The precise positioning of timestamps depends on the multiplexor and the encapsulated elementary video track.

Mismatch in frame rate values leads to differences in duration and bitrate.
The precise rate used in a player or transcoder depends on a specific implementation.

Average bitrate

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track 1

Determines the average bitrate of an elementary video track and checks that it matches the scenario in the template:

If only the minimum value is set, then this test ensures that bitrate is not below the specified value;
If only the maximum value is set, then this test ensures that bitrate doesn't exceed the specified value;
When both values are provided, this test ensures that bitrate is within the range between the minimum and maximum values inclusively—otherwise the test will be failed.

Bitrate is a number of bits used to transmit data per 1 second.
It can be measured in bit/s, kbit/s, Mbit/s.

CBR/VBR bitrate

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CBR VBR

Determines the bitrate type of video tracks and checks that it matches the template value.
The default value is VBR.
There are 2 types of bitrate depending on the video encoding method:

CBR (Constant bitrate) is an encoding method when the bitrate stays the same throughout the entire file;
VBR (Variable bitrate) is an encoding method when bitrate values can change throughout the entire file depending on the scene complexity.

CBR is used in IPTV and DVB/ATSC streams. VOD content usually relies on VBR since it lets you achieve a better quality due to a more optimal use of the bitrate by the encoder.

In the AVC/H.264 and HEVC/H.265 video formats, the declared CBR/VBR method can be determined by checking the cbr_flag value in the Sequence Parameter Set header.
The actual method can be identified by checking the size of all frames in a range of a second.

GOP length

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track 1

Determines the GOP length value in elementary video tracks and checks that it matches the template value:

If only a minimum value is set, it is checked that the GOP length is not less than this value;
If only a maximum value is set, it is checked that the GOP length doesn't exceed this value;
When both values are provided, it is checked that the GOP length is in the range between the maximum and minimum values inclusively.

GOP (group of pictures) is a sequence of frames in an elementary video track. The sequence comprises I-, P- and B-frames.
GOP length is the distance between 2 key I-frames.

In IPTV/DVB/ATSC streams, the GOP length doesn't exceed 1–2 seconds. For frame rate = 25, it is 25–50 frames, respectively. This is due to inserting service PSI/SI tables, as well as the speed at which the stream playback starts (the player starts to play the stream with a reference frame, and the longer the GOP, the higher the delay when switching to another channel).
In OTT, it is acceptable to have one reference frame per segment, and the segment length may vary significantly.
For VOD content, the GOP length values may be quite high.

GOP structure

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track 1

Determines the GOP structure in video tracks and checks that it matches the template value.
A GOP structure shows the distance between I-, P- and B-frames. It is set using two values:

M is a distance between two P-frames;
N is a distance between two I-frames.

For example, the M=4; N=25 structure means that each twenty-fifth frame is an I-frame, each fourth frame is a P-frame, and there are 3 B-frames between them. The result is the following GOP structure:
IPBBBPBBBPBBBPBBBPBBBPBBBI.

Closed GOP

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track 1
closed GOP structure opened GOP structure

Checks that the GOP structure in video tracks matches the template value.
There is an open and a closed GOP structure.
In a closed GOP, all P- and B-frames reference the frames of the same GOP.
An open GOP may contain P- and B-frames that reference the frames of another GOP.
The checker determines the GOP type using the syntax of the key frames.
Checked values:

the MPEG-1 and MPEG-2 video formats: the closed_gop value in the Group of Picture Header;
the AVC/H.264 video format: the slice_type and nal_unit_type values in the Slice Header and the syntax of reference frames for P- and B-frames. The probe explicitly pinpoints a closed GOP by checking if the IDR flag is present in an I-frame;
the HEVC/H.265 video format: the nal_unit_type value in the Slice Header and the syntax of reference frames for P- and B-frames.

Video bit depth

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8 bit 10 bit 12 bit 16 bit

Checks that the bit depth value in the headers of video tracks matches the template value.
The default value is 8 bits.
Bit depth is the number of bits used to describe the luminance (Y) and chrominance components (Cb, Cr) of one pixel.
Common bit depth values are:

8 bits — the most common digital broadcasting format supported by the MPEG-1 and MPEG-2 video formats;
10 bits — usually used in the combination of HEVC/H.265 video format, 4K resolution and HDR;
8–12 bits — supported by the AVC/H.264 video format depending on the Profile value;
8–16 bits — supported by the HEVC/H.265 video format depending on the Profile value.

For AVC/H.264 and HEVC/H.265 video formats, the bit_depth_luma_minus8 and bit_depth_chroma_minus8 values in the Sequence Parameter Set header are checked. Value interpretation: 0 — 8 bits, 2 — 10 bits, 4 — 12 bits, 6 — 16 bits.

Video bit depth changed

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Detects changes of the bit depth values in the headers of elementary tracks.
A change in bit depth leads to changes in video and may result in the player decoder or transcoder crash or reinitialization with service interruption.

Type of entropy coding

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CABAC CAVLC

Checks that the type of entropy coding in the headers of AVC/H.264 video tracks matches the template value.
The default value is CABAC.
This test targets AVC/H.264 video tracks only:

MPEG-1 and MPEG-2 video formats use VLC (Variable-Length Coding), making this test irrelevant for them;
HEVC/H.265 video format uses CABAC, making this test irrelevant for it as well;
AVC/H.264 relies on 2 coding algorithms:
CAVLC or context-adaptive variable-length coding;
CABAC or context-adaptive binary arithmetic coding. It is available for certain Profile values, for example Main and High. It achieves a 10–15% bitrate reduction compared to CAVLC at the same quality, but increases computational complexity.

For the AVC/H.264 video format, the entropy_coding_mode_flag value in the Picture Parameter Set header is checked.

Type of entropy coding changed

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Detects changes of the entropy coding type in the Picture Parameter Set header for AVC/H.264 video tracks.
A change in the entropy coding type results in the video syntax change and may result in the player decoder or transcoder crash or reinitialization with service interruption.

Reference frame number

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track 1

Checks that the maximum number of reference frames in the headers of video tracks matches the template value.

Reference frames are used by the encoder to predict frames in the process of compression. They are then used by the decoder to restore frames.

This check can be used for AVC/H.264 and HEVC/H.265 video formats since MPEG-1 and MPEG-2 have one reference frame for P-frames and two reference frames for B-frames (MPEG-2), i.e. one preceding and one following frame.
AVC/H.264 and HEVC/H.265 can have up to 16 reference frames.
An optimal option is between 3 to 6 frames. A bigger number of frames usually takes up space in a buffer, but is not actually used, which means the settings are imperfect.
Checked values:

the AVC/H.264 video format: the max_num_ref_frames value in the Sequence Parameter Set header;
the HEVC/H.265 video format: the sps_max_dec_pic_buffering_minus1 value in the Sequence Parameter Set header.

Reference frame number changed

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Detects changes in the maximum number of reference frames in the headers of elementary video tracks.
A change in the maximum number of reference frames may result in a crash or reinitialization of the player decoder or transcoder with service interruption.

HDR format

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HDR10 HLG HDR10+ Dolby Vision

Checks that the HDR format in the headers of video tracks matches the template value.

This check is applicable to AVC/H.264 and HEVC/H.265.
HDR content usually uses the HEVC/H.265 video format with the Bit Depth value equal to 10 bits and 4K video resolution. It is possible to use AVC/H.264, but this is rare in practice. Bit Depth that equals to 8 bits is almost not used for HDR content.

There are 4 key HDR standards:

HDR10 is a widely used open standard with a set of static metadata;
HLG is a widely used open standard without metadata;
HDR10+ is a proprietary standard by Samsung that includes a set of dynamic metadata and has backward compatibility with HDR10.
Dolby Vision is a proprietary standard from Dolby Laboratories that includes a set of dynamic metadata. Some Dolby Vision profiles have backward compatibility with HDR10 and HLG;

For AVC/H.264 and HEVC/H.265 video formats, the following values are checked: Sequence Parameter Set, the colour_primaries, transfer_characteristics and matrix_coeffs values, SEI: Mastering display colour volume, Content light level information, Alternative transfer characteristics, user_data_registered_itu_t_t35.

HDR10 metadata

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cd/m2 cd/m2 cd/m2 cd/m2

Checks that HDR10 metadata in the headers of elementary video tracks matches the template values.
Default values:
Display primaries [0] — 0.170; 0.797
Display primaries [1] — 0.131; 0.046
Display primaries [2] — 0.708; 0.292
White Point — 0.3127; 0.329
Max display mastering luminance — 1000
Min display mastering luminance — 0.005
Maximum Content Light Level (MaxCLL) — 1000
Maximum Frame-Average Light Level (MaxFALL) — 400

HDR10 metadata includes Mastering display colour volume and Content light level information values.
Mastering display colour volume is reference display parameters used to create video content. During video content playback, the display will be readjusted according to the reference.
Mastering display colour volume describes:

Display primaries are Х and Y coordinates of the three primary chrominance components;
White Point are X and Y coordinates of the white point;
Max display mastering luminance is the nominally maximum luminance of the mastering display in cd/m2. In accordance with SMPTE ST 2086:2018, this parameter can receive integer values in the 5–10000 cd/m2 range, where 1 cd/m2 equals 1 nit (nt);
Min display mastering luminance is the nominally minimum luminance of the mastering display in cd/m2. In accordance with SMPTE ST 2086:2018, this parameter can receive fractional values in the 0.0001–5.0000 cd/m2 range, where 1 cd/m2 equals 1 nit (nt).

Content light level information is the value of the upper boundary of the nominal target luminance level of the images. It includes:

Maximum Content Light Level (MaxCLL) is a parameter that indicates the upper boundary of the maximum pixel luminance level in cd/m2. 1 cd/m2 equals 1 nit (nt);
Maximum Frame-Average Light Level (MaxFALL) is a parameter that indicates the upper boundary of the maximum average luminance level of the whole frame in cd/m2. 1 cd/m2 equals 1 nit (nt).

HDR10 metadata changed

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Detects changes of HDR10 metadata values in the headers of elementary video tracks.
A change in values of HDR10 metadata will lead to a change in color rendering on the output device. The viewer will most likely notice this.
Color rendering also depends on colorimetric parameters. Their change is detected in the Colorimetric parameters changed test.

Video freeze

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Video freeze detecting interval

ms

Video freeze sensitivity (PSNR threshold)

dB

Do not test during special time slots:

Time from the start of the file

Time from the end of the file

Detects video freezes within a given period of time.
A state of error occurs if a static image persists during the given interval (in milliseconds).

Special time slots let you specify time periods at the start and/or the end of the file, which will be skipped during test.

The sensitivity of the freeze detector is set with the threshold value of the frame similarity degree based on the PSNR (peak signal-to-noise ratio) metric in decibels. The detector calculates the PSNR between two consecutive frames. If PSNR exceeds the threshold, the frames are considered identical. If all frames are identical during the interval when a freeze is detected, the state of error occurs. The higher the threshold, the stricter the condition for similarity of adjacent frames.

Sensitivity to video freezes. The default value is 42 dB.
An interval for video freeze detection. The default value is 1000 milliseconds.

For information:
PSNR 20 means the frames are similar, but there is still some significant difference;
PSNR 35 means the frames are similar, but there are some visual differences;
PSNR 42 is the upper limit of error perception by the human eye;
PSNR 60–100 means the frames are almost identical.

Black Frames

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Black Luminance Level

Black pixel ratio in frame

%

Black Frames Interval

ms

Do not test during special time slots:

Time from the start of the file

s

Time from the end of the file

s

Detects black frames in the video track. The algorithm analyzes frames based on specified threshold values: Black Luminance Level and Black pixel ratio in frame. If frames remain black longer than the defined Black Frames Interval, the test is considered failed.
Default values:

Black Luminance Level – 16. The luminance component threshold that determines which pixels are considered black.
Black pixel ratio in a frame – 95% The threshold percentage of black pixels in a frame. If exceeded, the frame is considered black. Adjusting this threshold allows for the detection of black frames with logos or other minor deviations.
Black Frames Interval – 1000 ms. The minimum duration in milliseconds during which frames remain black.

Exceptions allow you to specify time intervals at the beginning and/or end of the file that will be skipped during the Test perform.

Constant-Color Frames

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Constant-color pixel ratio in a frame

%

Constant-Color Frames Interval

ms

Do not test during special time slots:

Time from the start of the file

s

Time from the end of the file

s

Detects frames in a video track where all pixels are mostly the same color. The algorithm analyzes frames and compares the percentage of constant-color pixels to the threshold. If frames remain constant-colored longer than the specified interval, the test is considered failed.
Default values:

Constant-color pixel ratio in a frame — 90%. The threshold percentage of the same color pixels in a frame. If exceeded, the frame is considered constant-color. Adjusting this parameter allows for the detection of frames with logos or minor color variations.
Constant-Color Frames Interval – 1000 ms. The minimum duration in milliseconds during which frames remain constant-colored.

Exceptions allow you to specify time intervals at the beginning and/or end of the file that will be skipped during the Test perform.

Color bars test pattern

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Absolute Color bar detection coefficient

%

Relative Color bar detection coefficient

%

Сolor bar frames interval

ms

Do not test during special time slots:

Time from the start of the file

s

Time from the end of the file

s

Detects frames in the video track containing a color bars test pattern (EBU and SMPTE Color Bars). The algorithm analyzes frames using two coefficients. If frames contain color bar test pattern for longer than the specified interval, the test is considered failed.
Default value:

Absolute Color bar detection coefficient – 40%
Relative Color bar detection coefficient – 10%
Сolor bar frames interval – 1000 ms. The minimum duration in milliseconds during which frames contain color bars test pattern.

Exceptions allow you to specify time intervals at the beginning and/or end of the file that will be skipped during the Test perform.

Video decodability error

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Mode

Correct frames percentage is less than

%

Determines the possibility of decoding the video track. The system reports an error when the number of correctly decoded frames is below the given threshold in relation to the frame rate.
The default value is 100%.
The default mode is Full.
The metric allows you to estimate the possibility of decoding the video stream. The number of correctly decoded frames is compared to the specified frame rate.
The metric is implemented in two modes:

Lite involves a semantic analysis of the elementary stream without further decoding; the accuracy of measurement and the resource consumption are average. This level is enough to estimate the possibility of decoding the stream, but it doesn't factor in the issues inside the frame;
Full involves full decoding; the accuracy of measurement and the resource consumption are high. On this level, the frame correctness is confirmed by its full decoding.

Audio sample rate

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24000 Hz 44100 Hz 48000 Hz 96000 Hz Hz

Checks that the value of audio sample rate in the headers of audio tracks matches the template value.
The default value is 48000 Hz:
Audio sample rate is a number of samples played in one second. It is measured in Hertz (Hz):

44100 Hz — the standard used mainly in music streaming platforms;
48000 Hz — the most wide-spread standard, covers up to 90% of needs in digital television and streaming services;
96000 Hz — used for in-studio works. Also used for high-quality Blu-ray audio tracks.

Audio bit depth

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16 bit 20 bit 24 bit 36 bit

Checks that the audio bit depth value in the headers of audio tracks matches the template value.
Default value is 16
The most wide-spread are:

16 bit — professional standard for TV, streaming services and music streaming platforms;
24 бит — mainly used for in-studio records and Hi-Res, lossless audio.

Number of audio channels

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1 2 4 6

Checks that the number of audio channels in the headers of audio tracks matches the template value.
The default value is 2.

Usually, there are the following values:
1 — Mono — 0: М: mono;
2 — Stereo — 0: L: left, 1: R: right;
4 — Quadro — 0: L: left, 1: R: right, 3: SL: surround left, 4: SR: surround right;
6 — 5.1 — 0: L: left, 1: R: right, 2: C: central, 3: LFE: subwoofer, 4: SL: surround left, 5: SR: surround right;
8 — 7.1 — 0: L: left, 1: R: right, 2: C: central, 3: LFE: subwoofer, 4: SL: surround left, 5: SR: surround right, 6: BL: back left, 7: BR: back right.

AAC audio profile

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track 2
Main LC SSR LTP HE-AAC HE-AAC v2

Checks that the audio profile value in the headers of audio tracks matches the value in the template.
This test targets the AAC audio format.
The default value is LC.

Audio language tag

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track 2

Checks that the values of language descriptors in the container file match the template values.
The values of language descriptors are defined in the ISO 639-2 standard.

MPEG audio layer

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1 2 3

Checks that the values of Layer for MPEG Audio match the template values.
The default value is 3.

Layer I and Layer II are still used in the classic digital television (DVB).
Layer III (mp3) is widely spread in music streaming platforms, though it did take second place to the AAC audio format.

Audio decodability error

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Decoded audio bitrate / declared bitrate is less than

%

Determines the possibility of decoding an audio track. The system reports an error when the ratio between the bitrate of the decoded audio stream and the specified bitrate (channels * sample_rate * sample_size(bit)) is below the threshold.
The default value is 100%.

Audio silence

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Short-term loudness lower than

LUFS

Do not test during special time slots:

Time from the start of the file

s

Time from the end of the file

s

Detects silence in an audio track. The audio track is present, but its short-term loudness is below the threshold.
The default value is -70 LUFS.

Exceptions allow you to specify time intervals at the beginning and/or end of the file that will be skipped during the Test perform.
-70 LUFS is the de facto standard for detecting silence. In their recommendations, EBU R128 and ATSC A/85 rely on this value.

Momentary loudness

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Severity level:

Target loudness level

LUFS

Tolerance

LU

Checks that the momentary loudness value matches the specified threshold values.
The default values for the target momentary loudness and permissible deviations according to the EBU R128 standard are -23 LUFS, +/- 1 LU.
LUFS (Loudness Unit Full Scale), according to EBU R 128, is the logarithmic sound level unit relative to the full-scale value (LUFS is similar to LKFS, which is used in ITU-R BS 1770).
LU is a loudness unit: according to EBU R 128, 1 LU equals 1 dB.

Momentary Loudness is a value of loudness measured using the sliding window technique with integration time equal to 400 ms, according to EBU Tech Doc 3341. The measurement unit is LUFS.
Momentary loudness and Short-term loudness are used in addition to the Programme loudness to control the current programme dynamics.

Short-Term loudness

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Severity level:

Target loudness level

LUFS

Tolerance

LU

Checks that the short-term loudness value matches the specified threshold values.
The default values for the target short-term loudness and permissible deviations according to the EBU R128 standard are -23 LUFS, +/- 1 LU.
LUFS (Loudness Unit Full Scale), according to EBU R 128, is the logarithmic sound level unit relative to the full-scale value (LUFS is similar to LKFS, which is used in ITU-R BS 1770).
LU is a loudness unit: according to EBU R 128, 1 LU equals 1 dB.

Short-Term Loudness is a value of loudness measured using the sliding window technique with integration time equal to 3000 ms, without using relative gating according to the EBU Tech Doc 3341 standard.
Momentary loudness and Short-term loudness are used in addition to Programme loudness to control the current programme dynamics.
Recommended values:

According to EBU R128 — −23 LUFS, +/− 1 LU;
According to ATSC A/85 (USA) — −24 LUFS, +/− 1 LU;
According to Free TV Australia OP-59 (Australia) и ATSC A/85 (USA) — −24 LUFS, +/− 1 LU;
According to ARIB TR-B32 (Japan) — −23 LUFS, +/− 1 LU.

Programme Loudness

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Severity level:

Target loudness level

LUFS

Tolerance

LU

Checks that the value of programme loudness matches the specified threshold values.
The default values for the target loudness and permissible deviations according to the EBU R128 standard are -23 LUFS, +/- 1 LU.
LUFS (Loudness Unit Full Scale), according to EBU R 128, is the logarithmic sound level unit relative to the full-scale value (LUFS is similar to LKFS, which is used in ITU-R BS 1770).
LU is a loudness unit: according to EBU R 128, 1 LU equals 1 dB.

Programme loudness is an average (integral) loudness throughout the entire programme duration; the loudness level is the value of programme loudness in LUFS.
Recommended values:

According to EBU R128 — −23 LUFS, +/− 1 LU;
According to ATSC A/85 (USA) — −24 LUFS, +/− 1 LU;
According to Free TV Australia OP-59 (Australia) и ATSC A/85 (USA) — −24 LUFS, +/− 1 LU;
According to ARIB TR-B32 (Japan) — −23 LUFS, +/− 1 LU.

Loudness Range

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Minimum

LU

Maximum

LU

Checks that the loudness values match the specified threshold values.

Loudness range is a parameter determining a dynamic audio range calculated by a statistical technique according to the EBU Tech Doc 3342 and ITU-R BS.1770-3. The measurement unit is LU. 1 LU is equivalent to 1 dB.
The short-term loudness values are basically the data source for measuring the loudness range.
According to the ITU-R BS.1770 standard referenced by EBU R128 (Europe), ATSC A/85 (USA), Free TV Australia OP-59 (Australia), and ARIB TR-B32 (Japan), the specific value may vary depending on the use context, but the most common range is 0–6 LU.

Maximum Permitted True Peak level

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Maximum Permitted True Peak level

dBTP

Checks that peak values of a digital audio signal match the specified threshold value.
The default value according to the EBU R128 standard is -1 dBTP.
It is recommended to support the true peak level of no more than -3 dBTP.

Maximum Permitted True Peak Level is the maximum permitted level of true peak values in a digital audio signal calculated using the True Peak algorithm according to the ITU-R BS.1770 recommendation. The unit of measurement is dBTP.
Recommended values:

According to EBU R128 — −1 dBTP. It is recommended for true peak level to be no larger than -3 dBTP;
According to ATSC A/85 (USA) — −2 dBTP. Maximum Permitted True Peak Level is legally mandated by the Federal Communications Commission (FCC) requirements under the CALM (The Commercial Advertisement Loudness Mitigation) Act;
According to Free TV Australia OP-59 (Australia) — −2 dBTP;
According to ARIB TR-B32 (Japan) — −1 dBTP.

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