- 0 |
- NULL |
- |
-
-
- 1 |
- AAC Main |
- Main |
-
-
- 2 |
- AAC LC (Low Complexity) |
- Main, Scalable, HQ, LD v2, AAC, HE-AAC, HE-AAC v2 |
-
-
- 3 |
- AAC SSR (Scalable Sampling Rate) |
- Main |
+ cccc |
+
+
+ A four-character code indicating which indicates which of the possible codecs is being described.
+ Potential values are:
+
+
+
+ Four-character codes for WebM-supported codecs
+
+
+
+ Four-character code |
+ Codec |
+
+
+
+
+ vp08 |
+ VP8 |
+
+
+ vp09 |
+ VP9 |
+
+
+ vp10 |
+ VP10 |
+
+
+
+ |
- 4 |
- AAC LTP (Long Term Prediction) |
- Main, Scalable, HQ |
+ PP |
+
+
+ The two-digit profile number, padded with leading zeroes if necessary to be exactly two digits.
+
+
+
+ WebM profile numbers
+
+
+
+ Profile |
+ Description |
+
+
+
+
+ 00 |
+
+ Only 4:2:0 (chroma subsampled both horizontally and vertically).
+ Allows only 8 bits per color component.
+ |
+
+
+ 01 |
+
+ All chroma subsampling formats are allowed.
+ Allows only 8 bits per color component.
+ |
+
+
+ 02 |
+
+ Only 4:2:0 (chroma subsampled both horizontally and vertically).
+ Supports 8, 10, or 12 bits per color sample component.
+ |
+
+
+ 03 |
+
+ All chroma subsampling formats are allowed.
+ Supports 8, 10, or 12 bits per color sample component.
+ |
+
+
+
+ |
- 5 |
- SBR (Spectral Band Replication) |
- HE-AAC, HE-AAC v2 |
+ LL |
+
+ The two-digit level number.
+ The level number is a fixed-point notation, where the first digit is the ones digit, and the second digit represents
+ tenths.
+ For example, level 3 is 30 and level 6.1 is 61 .
+ |
- 6 |
- AAC Scalable |
- Main, Scalable, HQ |
+ DD |
+
+ The bit depth of the luma and color component values; permitted values are 8, 10, and 12.
+ |
- 7 |
- TwinVQ (Coding for ultra-low bit rates) |
- Main, Scalable |
+ CC |
+
+
+ A two-digit value indicating which chroma subsampling format to use.
+ The following table lists permitted values; see [Chroma subsampling](/en-US/docs/Web/Media/Formats/Video_concepts#chroma_subsampling) in our "Digital video concepts" guide for additional information about this topic and others.
+
+
+
+ WebM chroma subsampling identifiers
+
+
+
+ Value |
+ Chroma subsampling format |
+
+
+
+
+ 00 |
+
+ 4:2:0 with the chroma samples sited interstitially between the pixels
+ |
+
+
+ 01 |
+
+ 4:2:0 chroma subsampling with the samples collocated with luma (0, 0)
+ |
+
+
+ 02 |
+
+ 4:2:2 chroma subsampling (4 out of each 4 horizontal pixels' luminance are used)
+ |
+
+
+ 03 |
+
+ 4:4:4 chroma subsampling (every pixel's luminance and chrominance are both retained)
+ |
+
+
+ 04 |
+ Reserved |
+
+
+
+ |
- 8 |
- CELP (Code-Excited Linear Prediction) |
- Main, Scalable, Speech, HQ, LD |
+ cp |
+
+
+ A two-digit integer specifying which of the color primaries from Section 8.1 of the ISO/IEC 23001-8:2016 standard.
+ This component, and every component after it, is optional.
+
+ The possible values of the color primaries component are:
+
+
+ ISO/IEC Color primary identifiers
+
+
+
+ Value |
+ Details |
+
+
+
+
+ 00 |
+ Reserved for future use by ITU or ISO/IEC |
+
+
+ 01 |
+
+ BT.709, sRGB, sYCC. BT.709 is the standard for high definition (HD) television; sRGB is the most common color space used for computer displays.
+ Broadcast BT.709 uses 8-bit color depth with the legal range being from 16 (black) to 235 (white).
+ |
+
+
+ 02 |
+
+ Image characteristics are unknown, or are to be determined by the application
+ |
+
+
+ 03 |
+ Reserved for future use by ITU or ISO/IEC |
+
+
+ 04 |
+
+ BT.470 System M, NTSC (standard definition television in the United States)
+ |
+
+
+ 05 |
+
+ BT.470 System B, G; BT.601; BT.1358 625; BT.1700 625 PAL and 625 SECAM
+ |
+
+
+ 06 |
+
+ BT.601 525; BT.1358 525 or 625; BT.1700 NTSC; SMPTE 170M.
+ Functionally identical to 7 .
+ |
+
+
+ 70 |
+
+ {{Glossary("SMPTE")}} 240M (historical).
+ Functionally identical to 6 .
+ |
+
+
+ 08 |
+ Generic film |
+
+
+ 09 |
+
+ BT.2020; BT.2100.
+ Used for ultra-high definition (4K) High Dynamic Range (HDR) video, these have a very wide color {{glossary("gamut")}} and support 10-bit and 12-bit color component depths.
+ |
+
+
+ 10 |
+
+ SMPTE ST 428 (D-Cinema Distribution Master: Image characteristics).
+ Defines the uncompressed image characteristics for DCDM.
+ |
+
+
+ 11 |
+
+ SMPTE RP 431 (D-Cinema Quality: Reference projector and environment).
+ Describes the reference projector and environment conditions that provide a consistent film presentation experience.
+ |
+
+
+ 12 |
+
+ SMPTE EG 432 (Digital Source Processing: Color Processing for D-Cinema).
+ Engineering guideline making color signal decoding recommendations for digital movies.
+ |
+
+
+ 13 – 21 |
+ Reserved for future use by ITU-T or ISO/IEC |
+
+
+ 22 |
+ EBU Tech 3213-E |
+
+
+ 23 – 255 |
+ Reserved for future use by ITU-T or ISO/IEC |
+
+
+
+ |
+
+
+ tc |
+
+ A two-digit integer indicating the
+ transferCharacteristics for the video.
+ This value is from Section 8.2 of ISO/IEC 23001-8:2016, and indicates the transfer characteristics to be used when adapting the decoded color to the render target.
+ |
+
+
+ mc |
+
+ The two-digit value for the matrixCoefficients property.
+ This value comes from the table in Section 8.3 of the ISO/IEC 23001-8:2016 specification.
+ This value indicates which set of coefficients to use when mapping from the native red, blue, and green primaries to the luma and chroma signals.
+ These coefficients are in turn used with the equations found in that same section.
+ |
+
+
+ FF |
+
+ Indicates whether to restrict the black level and color range of each color component to the legal range.
+ For 8-bit color samples, the legal range is 16-235.
+ A value of 00 indicates that these limitations should be enforced, while a value of 01 allows the full range of possible values for each component, even if the resulting color is out of bounds for the color system.
+ |
+
+
+