Welcome to Doom9's Forum, THE in-place to be for everyone interested in DVD conversion.

Before you start posting please read the forum rules. By posting to this forum you agree to abide by the rules.

 

Go Back   Doom9's Forum > Capturing and Editing Video > New and alternative a/v containers

Reply
 
Thread Tools Search this Thread Display Modes
Old 12th April 2022, 11:49   #1  |  Link
PCU
Registered User
 
Join Date: Oct 2017
Posts: 327
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?
PCU is offline   Reply With Quote
Old 12th April 2022, 14:05   #2  |  Link
richardpl
Registered User
 
Join Date: Jan 2012
Posts: 271
There is big difference in number of security related bugs.
richardpl is offline   Reply With Quote
Old 13th April 2022, 10:53   #3  |  Link
PCU
Registered User
 
Join Date: Oct 2017
Posts: 327
Quote:
Originally Posted by richardpl View Post
There is big difference in number of security related bugs.
Is that all the difference?
PCU is offline   Reply With Quote
Old 14th April 2022, 03:11   #4  |  Link
huhn
Registered User
 
Join Date: Oct 2012
Posts: 7,921
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.
huhn is offline   Reply With Quote
Old 19th April 2022, 15:37   #5  |  Link
FranceBB
Broadcast Encoder
 
FranceBB's Avatar
 
Join Date: Nov 2013
Location: Royal Borough of Kensington & Chelsea, UK
Posts: 2,902
Quote:
Originally Posted by huhn View Post
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
FranceBB is offline   Reply With Quote
Old 22nd April 2022, 12:45   #6  |  Link
tormento
Acid fr0g
 
tormento's Avatar
 
Join Date: May 2002
Location: Italy
Posts: 2,566
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.
__________________
@turment on Telegram
tormento is offline   Reply With Quote
Old 22nd April 2022, 13:16   #7  |  Link
richardpl
Registered User
 
Join Date: Jan 2012
Posts: 271
Learn sometimes to use -c:a pcm_s32le
richardpl is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 23:41.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.