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Old 12th April 2022, 11:49   #1  |  Link
PCU
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FFmpeg vs official decoders question

Is there really a difference between official decoders and FFmpeg, such as file decoding quality: Xiph's official/MainConcept's vs FFmpeg?
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Old 12th April 2022, 14:05   #2  |  Link
richardpl
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There is big difference in number of security related bugs.
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Old 13th April 2022, 10:53   #3  |  Link
PCU
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There is big difference in number of security related bugs.
Is that all the difference?
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Old 14th April 2022, 03:11   #4  |  Link
huhn
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there is also speed and even quality to some very low degree.

for example decoding lossy audio to float instead of integer.
the majority of video codecs and pretty much all new ones are decoded bit perfect.
the last codec that i remember that is not bit perfect when decoded is mpeg2 so the decoder had effect on image quality. else it is just speed or feature level of modern codecs if there is still a difference it is pretty much bug.

there is also error correction for broadcast but that's quite complicated and a matter of who is better at blurring the image.
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Old 19th April 2022, 15:37   #5  |  Link
FranceBB
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Quote:
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there is also error correction for broadcast but that's quite complicated
Yeah, for instance there's a matter of coping with CRC Errors, wrong frame location / reference line for DolbyE etc, however the overwhelming majority of official decoders for broadcast are hardware decoders and they can be extremely picky about what the source is and about buffer overflows. I find software decoding to be much more resilient than hardware decoding, especially when it comes to buffering fluctuation.

Just a few days ago I had to fight with this for an H.264 file I had to send to a very very picky hardware decoder: https://forum.doom9.org/showthread.php?t=184045
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Old 22nd April 2022, 12:45   #6  |  Link
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Talking about audio, ffmpeg has the habit to decode anything to 16 bits, even when the source is 24 bits.

For FLAC, to be clear, I plainly use the FLAC compressor, in reverse way.
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Old 22nd April 2022, 13:16   #7  |  Link
richardpl
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Learn sometimes to use -c:a pcm_s32le
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