[FFmpeg-user] How to concatenate multiple mp4 files without re-encoding to an intermediate format

[Dennis]

On 8/31/12, Rares Pop <raresp at axz.ro> wrote:
> Tom,
>
> Many thanks !
> With a minor correction (required by ffmpeg) it worked.
> ffmpeg -i "concat:concat.ts|concat2.ts" -c copy -absf aac_adtstoasc
> concatAll.mp4
>
> All of the commands executed very fast since no re-encoding was necessary.
> This was our goal after all since we're processing a lot files. Adding round
> of transcoding was not an option.
> Thanks again.
>
> Rares
>
>
> On Aug 31, 2012, at 2:56 PM, Tom Evans <tevans.uk at googlemail.com> wrote:
>
>> On Fri, Aug 31, 2012 at 11:33 AM, Carl Eugen Hoyos <cehoyos at ag.or.at>
>> wrote:
>>> Rares Pop <raresp <at> axz.ro> writes:
>>>
>>>> ffmpeg -i concat:'file1.mp4|file2.mp4' -vcodec copy -acodec copy  -y
>>>> asset.mp4
>>>
>>>> Result: asset.mp4 file is the same as file1.mp4.It behaves
>>>> like it ignores file2.mp4
>>>
>>> So it seems that this is unsupported.
>>> You can try to concatenate the raw h264 and the raw aac streams
>>> and mux the resulting streams but this may lead to A/V desync
>>> (that you can try to eliminate by cutting the streams or inserting
>>> silence but this will have to be done manually).
>>>
>>> Please do not top-post here, Carl Eugen
>>>
>>
>> Would re-muxing to TS as an intermediate help with this? Seems to work
>> ok..
>>
>> ffmpeg -i source1.mp4 -c copy -bsf h264_mp4toannexb -t 30 out1.ts
>> ffmpeg -i source2.mp4 -c copy -bsf h264_mp4toannexb -t 30 out2.ts
>> ffmpeg -i "concat:out1.ts|out2.ts" -c copy out.mp4
>> ffprobe out.mp4 2>&1| grep Duration
>>  Duration: 00:01:00.08, start: 0.000000, bitrate: 2086 kb/s
>>
>> Cheers
>>
>> Tom
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>
> ---------------------
> Rares Pop
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