[FFmpeg-trac] #4354(undetermined:new): Big file size difference after using -c:v copy and -c:a copy
FFmpeg
trac at avcodec.org
Sun Mar 29 01:37:08 CET 2015
#4354: Big file size difference after using -c:v copy and -c:a copy
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Reporter: Atarikid | Owner:
Type: defect | Status: new
Priority: normal | Component: undetermined
Version: 2.5.2 | Resolution:
Keywords: | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
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Comment (by AndyF):
Replying to [ticket:4354 Atarikid]:
> I noticed some very strange when copying streams.
>
> You can reproduce this with any .m2t or .ts source file.
> Just copy the streams with -c:v copy -c:a copy
>
> Note the below example source file has 1 video stream and 1 audio
stream.
> Do notice the BITRATE has changed from 27253 kb/s to 19490 kb/s
> How can this be the case when you copy the streams?
Transport streams may contain null packets to pad out bandwidth to a fixed
value which could account for it.
I've never used one, but search for transport stream analyzer and I guess
you will be able to find something to look at your streams. Null packets
have pid 0x1fff (8191).
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Ticket URL: <https://trac.ffmpeg.org/ticket/4354#comment:3>
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