YUV4MPEG2 - Revision history

Artoria2e5 at 08:10, 31 December 2023

2023-12-31T08:10:50Z

← Older revision		Revision as of 01:10, 31 December 2023
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	:* <code>C420mpeg2</code> = 4:2:0 with vertically-displaced chroma planes (MPEG-2: B and R have same displacement of down 0.5 px)		:* <code>C420mpeg2</code> = 4:2:0 with vertically-displaced chroma planes (MPEG-2: B and R have same displacement of down 0.5 px)
	:* <code>C420</code> = 4:2:0. Not found in original spec, so interpretations differ:		:* <code>C420</code> = 4:2:0. Not found in original spec, so interpretations differ:
	:** with coincident chroma planes, according to ~~AV1~~ (arguably the more useful interpretation)		:** with coincident chroma planes, according to rav1e (arguably the more useful interpretation)
	:** with JPEG displacement, [https://github.com/FFmpeg/FFmpeg/blob/e9c93009fc34ca9dfcf0c6f2ed90ef1df298abf7/libavformat/yuv4mpegdec.c according to ffmpeg]		:** with JPEG displacement, [https://github.com/FFmpeg/FFmpeg/blob/e9c93009fc34ca9dfcf0c6f2ed90ef1df298abf7/libavformat/yuv4mpegdec.c according to ffmpeg] and aom.
	:* <code>C422</code> = 4:2:2 coincident		:* <code>C422</code> = 4:2:2 coincident
	:* <code>C444</code> = 4:4:4 coincident		:* <code>C444</code> = 4:4:4 coincident

Artoria2e5: /* Notes */ ~

2023-11-22T08:44:38Z

Notes: ~

← Older revision		Revision as of 01:44, 22 November 2023
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	== Notes ==		== Notes ==
	* FFmpeg yuv4mpegdec's interpretation of <code>C</code> sample locations surprisingly differ from the original. Instead of noting <code>C422</code> as coincidental, the decoder only reads "unknown".		* FFmpeg yuv4mpegdec's interpretation of <code>C</code> sample locations surprisingly differ from the original. Instead of noting <code>C422</code> as coincidental, the decoder only reads "unknown".
	* FFmpeg's yuv4mpegenc taxonomy uses <code>C420paldv</code> for "top-left", i.e. coincidental. This is obviously wrong~~. This is partially because~~ ffmpeg uses one <code>AvChromaLocation</code> to describe where ''both'' chroma samples are taken.		* FFmpeg's yuv4mpegenc taxonomy uses <code>C420paldv</code> for "top-left", i.e. coincidental. This is obviously wrong, but nothing can be done without sacrificing the real PAL-DV: ffmpeg uses one <code>AvChromaLocation</code> to describe where ''both'' chroma samples are taken.

	[[Category:Container Formats]]		[[Category:Container Formats]]

Artoria2e5: /* Notes */

2023-11-22T08:40:47Z

Notes

← Older revision		Revision as of 01:40, 22 November 2023
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	:** with coincident chroma planes, according to AV1 (arguably the more useful interpretation)		:** with coincident chroma planes, according to AV1 (arguably the more useful interpretation)
	:** with JPEG displacement, [https://github.com/FFmpeg/FFmpeg/blob/e9c93009fc34ca9dfcf0c6f2ed90ef1df298abf7/libavformat/yuv4mpegdec.c according to ffmpeg]		:** with JPEG displacement, [https://github.com/FFmpeg/FFmpeg/blob/e9c93009fc34ca9dfcf0c6f2ed90ef1df298abf7/libavformat/yuv4mpegdec.c according to ffmpeg]
	:* <code>C422</code> = 4:2:2 coincident ~~("unknown" according to ffmpeg... see the problem here?)~~		:* <code>C422</code> = 4:2:2 coincident
	:* <code>C444</code> = 4:4:4 coincident		:* <code>C444</code> = 4:4:4 coincident
	:* <code>C444alpha</code> = 4:4:4 plus a alpha channel of the same size (not supported by libwebm)		:* <code>C444alpha</code> = 4:4:4 plus a alpha channel of the same size (not supported by libwebm)
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	* frame length = width * height * 2 (4:2:2)		* frame length = width * height * 2 (4:2:2)
	* frame length = width * height * 3 (4:4:4)		* frame length = width * height * 3 (4:4:4)

			== Notes ==
			* FFmpeg yuv4mpegdec's interpretation of <code>C</code> sample locations surprisingly differ from the original. Instead of noting <code>C422</code> as coincidental, the decoder only reads "unknown".
			* FFmpeg's yuv4mpegenc taxonomy uses <code>C420paldv</code> for "top-left", i.e. coincidental. This is obviously wrong. This is partially because ffmpeg uses one <code>AvChromaLocation</code> to describe where ''both'' chroma samples are taken.

	[[Category:Container Formats]]		[[Category:Container Formats]]

Artoria2e5: aaa

2023-11-22T08:26:30Z

aaa

← Older revision		Revision as of 01:26, 22 November 2023
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	:** with coincident chroma planes, according to AV1 (arguably the more useful interpretation)		:** with coincident chroma planes, according to AV1 (arguably the more useful interpretation)
	:** with JPEG displacement, [https://github.com/FFmpeg/FFmpeg/blob/e9c93009fc34ca9dfcf0c6f2ed90ef1df298abf7/libavformat/yuv4mpegdec.c according to ffmpeg]		:** with JPEG displacement, [https://github.com/FFmpeg/FFmpeg/blob/e9c93009fc34ca9dfcf0c6f2ed90ef1df298abf7/libavformat/yuv4mpegdec.c according to ffmpeg]
	:* <code>C422</code> = 4:2:2 coincident		:* <code>C422</code> = 4:2:2 coincident ("unknown" according to ffmpeg... see the problem here?)
	:* <code>C444</code> = 4:4:4 coincident		:* <code>C444</code> = 4:4:4 coincident
	:* <code>C444alpha</code> = 4:4:4 plus a alpha channel of the same size (not supported by libwebm)		:* <code>C444alpha</code> = 4:4:4 plus a alpha channel of the same size (not supported by libwebm)

Artoria2e5: /* File header */ ~

2023-11-22T08:09:36Z

File header: ~

← Older revision		Revision as of 01:09, 22 November 2023
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	:* <code>C420mpeg2</code> = 4:2:0 with vertically-displaced chroma planes (MPEG-2: B and R have same displacement of down 0.5 px)		:* <code>C420mpeg2</code> = 4:2:0 with vertically-displaced chroma planes (MPEG-2: B and R have same displacement of down 0.5 px)
	:* <code>C420</code> = 4:2:0. Not found in original spec, so interpretations differ:		:* <code>C420</code> = 4:2:0. Not found in original spec, so interpretations differ:
	:** with coincident chroma planes, according to AV1		:** with coincident chroma planes, according to AV1 (arguably the more useful interpretation)
	:** with JPEG displacement, [https://github.com/FFmpeg/FFmpeg/blob/e9c93009fc34ca9dfcf0c6f2ed90ef1df298abf7/libavformat/yuv4mpegdec.c according to ffmpeg]		:** with JPEG displacement, [https://github.com/FFmpeg/FFmpeg/blob/e9c93009fc34ca9dfcf0c6f2ed90ef1df298abf7/libavformat/yuv4mpegdec.c according to ffmpeg]
	:* <code>C422</code> = 4:2:2 coincident		:* <code>C422</code> = 4:2:2 coincident

Artoria2e5: /* File header */

2023-11-22T08:06:52Z

File header

← Older revision		Revision as of 01:06, 22 November 2023
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	:* <code>C420paldv</code> = 4:2:0 with coincident R and vertically-displaced B (down 1 px)		:* <code>C420paldv</code> = 4:2:0 with coincident R and vertically-displaced B (down 1 px)
	:* <code>C420mpeg2</code> = 4:2:0 with vertically-displaced chroma planes (MPEG-2: B and R have same displacement of down 0.5 px)		:* <code>C420mpeg2</code> = 4:2:0 with vertically-displaced chroma planes (MPEG-2: B and R have same displacement of down 0.5 px)
	:* <code>C420</code> = 4:2:0 with coincident chroma planes ~~(not part of the original spec~~, ~~but made necessary by newer codec behavior)~~		:* <code>C420</code> = 4:2:0. Not found in original spec, so interpretations differ:
			:** with coincident chroma planes, according to AV1
			:** with JPEG displacement, [https://github.com/FFmpeg/FFmpeg/blob/e9c93009fc34ca9dfcf0c6f2ed90ef1df298abf7/libavformat/yuv4mpegdec.c according to ffmpeg]
	:* <code>C422</code> = 4:2:2 coincident		:* <code>C422</code> = 4:2:2 coincident
	:* <code>C444</code> = 4:4:4 coincident		:* <code>C444</code> = 4:4:4 coincident

Artoria2e5: /* File header */ ~

2023-11-22T08:01:43Z

File header: ~

← Older revision		Revision as of 01:01, 22 November 2023
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	; <code>C</code>, Colour space		; <code>C</code>, Colour space
	: Called "colorspace", actually defines pixel format and color model.		: Called "colorspace", actually defines pixel format and color model.
	:* <code>C420jpeg</code> = 4:2:0 with biaxially-displaced chroma planes		:* <code>C420jpeg</code> = 4:2:0 with biaxially-displaced chroma planes ("center": 0.5 right, 0.5 down)
	:* <code>C420paldv</code> = 4:2:0 with coincident R and vertically-displaced B		:* <code>C420paldv</code> = 4:2:0 with coincident R and vertically-displaced B (down 1 px)
	:* <code>C420mpeg2</code> = 4:2:0 with vertically-displaced chroma planes (MPEG-2: B and R have same displacement of down 0.5 px)		:* <code>C420mpeg2</code> = 4:2:0 with vertically-displaced chroma planes (MPEG-2: B and R have same displacement of down 0.5 px)
	:* <code>C420</code> = 4:2:0 with coincident chroma planes (not part of the original spec, but made necessary by newer codec behavior)		:* <code>C420</code> = 4:2:0 with coincident chroma planes (not part of the original spec, but made necessary by newer codec behavior)

Artoria2e5: /* File header */

2023-11-22T08:00:42Z

File header

← Older revision		Revision as of 01:00, 22 November 2023
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	: Called "colorspace", actually defines pixel format and color model.		: Called "colorspace", actually defines pixel format and color model.
	:* <code>C420jpeg</code> = 4:2:0 with biaxially-displaced chroma planes		:* <code>C420jpeg</code> = 4:2:0 with biaxially-displaced chroma planes
	:* <code>C420paldv</code> = 4:2:0 with vertically-displaced ~~chroma planes (PAL-DV: R coincident,~~ B ~~displaced down 1 pixel)~~		:* <code>C420paldv</code> = 4:2:0 with coincident R and vertically-displaced B
	:* <code>C420mpeg2</code> = 4:2:0 with vertically-displaced chroma planes (MPEG-2: B and R have same displacement of down 0.5 px)		:* <code>C420mpeg2</code> = 4:2:0 with vertically-displaced chroma planes (MPEG-2: B and R have same displacement of down 0.5 px)
	:* <code>C420</code> = 4:2:0 with coincident chroma planes		:* <code>C420</code> = 4:2:0 with coincident chroma planes (not part of the original spec, but made necessary by newer codec behavior)
	:* <code>C422</code> = 4:2:2		:* <code>C422</code> = 4:2:2 coincident
	:* <code>C444</code> = 4:4:4		:* <code>C444</code> = 4:4:4 coincident
	:* <code>C444alpha</code> = 4:4:4 plus a alpha channel of the same size (not supported by libwebm)		:* <code>C444alpha</code> = 4:4:4 plus a alpha channel of the same size (not supported by libwebm)
	:* <code>Cmono</code> = YCbCr plane only		:* <code>Cmono</code> = YCbCr plane only

Artoria2e5: ~

2023-11-22T07:30:09Z

← Older revision		Revision as of 00:30, 22 November 2023
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	:* <code>C420mpeg2</code> = 4:2:0 with vertically-displaced chroma planes (MPEG-2: B and R have same displacement of down 0.5 px)		:* <code>C420mpeg2</code> = 4:2:0 with vertically-displaced chroma planes (MPEG-2: B and R have same displacement of down 0.5 px)
	:* <code>C420</code> = 4:2:0 with coincident chroma planes		:* <code>C420</code> = 4:2:0 with coincident chroma planes
	:* <code>C422</code> = 4:2:2~~, coincident~~		:* <code>C422</code> = 4:2:2
	:* <code>C444</code> = 4:4:4		:* <code>C444</code> = 4:4:4
	:* <code>C444alpha</code> = 4:4:4 plus a alpha channel of the same size (not supported by libwebm)		:* <code>C444alpha</code> = 4:4:4 plus a alpha channel of the same size (not supported by libwebm)

Artoria2e5: /* File header */ ~

2023-11-22T07:28:56Z

File header: ~

← Older revision		Revision as of 00:28, 22 November 2023
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	: Called "colorspace", actually defines pixel format and color model.		: Called "colorspace", actually defines pixel format and color model.
	:* <code>C420jpeg</code> = 4:2:0 with biaxially-displaced chroma planes		:* <code>C420jpeg</code> = 4:2:0 with biaxially-displaced chroma planes
	:* <code>C420paldv</code> = 4:2:0 with vertically-displaced chroma planes (PAL-DV: ~~B and~~ R ~~have different~~, ~~alternate displacement~~)		:* <code>C420paldv</code> = 4:2:0 with vertically-displaced chroma planes (PAL-DV: R coincident, B displaced down 1 pixel)
	:* <code>C420mpeg2</code> = 4:2:0 with vertically-displaced chroma planes (MPEG-2: B and R have same displacement)		:* <code>C420mpeg2</code> = 4:2:0 with vertically-displaced chroma planes (MPEG-2: B and R have same displacement of down 0.5 px)
	:* <code>C420</code> = 4:2:0 with coincident chroma planes		:* <code>C420</code> = 4:2:0 with coincident chroma planes
	:* <code>C422</code> = 4:2:2, coincident		:* <code>C422</code> = 4:2:2, coincident