[FFmpeg-user] Problem "live" transcoding via piped input / Ceton InfiniTV 4

Dennis mediastream at gmail.com
Sun Mar 4 18:05:17 CET 2012


Try putting -threads 4 in front of -i, it will implement
multithreading for decoding.

On 3/3/12, Brian Johnson <ffmpeg-user at dogtoe.com> wrote:
> -preset ultrafast seems to help out tremendously, but I have a quad
> core CPU and even with -threads 4, 8, 10, etc I can't get ffmpeg to
> utilize the entire CPU (seems to max out at about 190%).
>
> - Brian
>
> On Fri, Mar 2, 2012 at 1:19 AM, dE . <de.techno at gmail.com> wrote:
>> On 03/02/12 00:37, Brian Johnson wrote:
>>>
>>> The command I am using: ffmpeg -i /dev/ctn91xx_mpeg0_0 -async 2
>>> -acodec libmp3lame -ac 2 -vcodec libx264 -s 1280x720 -aspect 16:9 -f
>>> mpegts file.ts
>>>
>>> The file /dev/ctn91xx_mpeg0_0 is actually the device (Ceton InfiniTV
>>> 4) itself where it returns a mpeg transport stream, basically a named
>>> pipe containing the raw audio and video.
>>>
>>> When I run the command below, I get tons of errors which repeats forever:
>>>
>>> ES packet size mismatch.0 size=     797kB time=00:00:04.23
>>> bitrate=1541.1kbits/s dup=25 drop=0
>>> [ac3 @ 0x8393340] frame CRC mismatch
>>> [mpeg2video @ 0x834e680] ac-tex damaged at 0 28
>>> [mpeg2video @ 0x834e680] ac-tex damaged at 2 1
>>> [mpeg2video @ 0x834e680] ac-tex damaged at 0 27
>>> [mpeg2video @ 0x834e680] ac-tex damaged at 0 29
>>> [mpeg2video @ 0x834e680] Warning MVs not available
>>> [mpeg2video @ 0x834e680] concealing 1276 DC, 1276 AC, 1276 MV errors
>>> [mpegts @ 0x8287aa0] PES packet size mismatch
>>> frame sync error 34 q=29.0 size=    1202kB time=00:00:05.76
>>> bitrate=1709.0kbits/s dup=145 drop=0
>>> Error while decoding stream #0:27
>>> ac-tex damaged at 4 2929.0 size=    1383kB time=00:00:09.17
>>> bitrate=1235.1kbits/s dup=145 drop=0
>>> [mpeg2video @ 0x834e680] mb incr damaged
>>> [mpeg2video @ 0x834e680] ac-tex damaged at 35 29
>>> [mpeg2video @ 0x834e680] concealing 880 DC, 880 AC, 880 MV errors
>>> [mpegts @ 0x8287aa0] PES packet size mismatch
>>> [ac3 @ 0x8393340] frame CRC mismatch
>>> [mpegts @ 0x8287aa0] PES packet size mismatch
>>>     Last message repeated 1 times
>>> [ac3 @ 0x8393340] frame sync error
>>> Error while decoding stream #0:27
>>> [mpeg2video @ 0x834e680] invalid cbp at 0 12
>>> [mpeg2video @ 0x834e680] mb incr damaged
>>> [mpeg2video @ 0x834e680] invalid mb type in B Frame at 3 24
>>> [mpeg2video @ 0x834e680] 00 motion_type at 1 25
>>> [mpeg2video @ 0x834e680] 00 motion_type at 0 26
>>> [mpeg2video @ 0x834e680] invalid mb type in B Frame at 16 27
>>>
>>> What is very interesting is that lower quality video transcodes (i.e.
>>> 320x240) has the same errors as above but only lasts about 1-2
>>> seconds, and then output looks normal
>>>
>>> frame= 1235 fps= 35 q=29.0 size=    1985kB time=00:00:39.53 bitrate=
>>> 411.2kbits/s dup=131 drop=0
>>>
>>> I believe this to be related to
>>> <https://lists.ffmpeg.org/pipermail/ffmpeg-user/2011-October/002584.html>
>>> and in my own research, I found that this may have been a regression
>>> from an older version, but again that is pure speculation on my part.
>>>
>>> Any ideas? :)
>>>
>>> - Brian
>>> _______________________________________________
>>> ffmpeg-user mailing list
>>> ffmpeg-user at ffmpeg.org
>>> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
>>
>>
>> Are you using the latest? This may be cause your PC is not as fast. Try
>> using -threads and -preset ultrafast.
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