[FFmpeg-devel] [PATCHv2] movenc: Write durations based on pts into mvhd/mdhd/tkhd/elst

[Martin Storsjö]

On Wed, 8 Jan 2020, Martin Storsjö wrote:

> On Fri, 20 Dec 2019, Michael Niedermayer wrote:
>
>> On Tue, Dec 17, 2019 at 03:15:09PM +0200, Martin Storsjö wrote:
>>> Keep all the existing data fields as they are (there's lots and
>>> lots of nontrivial calculation and heuristics based on them in
>>> their current form), but derive the duration as the difference
>>> between the pts of the first packet to the maximum pts+duration
>>> (not necessarily the last packet); use this duration in any box
>>> where the actual presentation duration is supposed to be.
>>>
>>> Fixes: 8420
>>> ---
>>> Fixed to fetch the duration for tmcd tracks from their designated
>>> source track.
>>> ---
>>>  libavformat/movenc.c | 35 ++++++++++++++++++++++++++++-------
>>>  1 file changed, 28 insertions(+), 7 deletions(-)
>>
>> I found another case that changes, again dont know which is more correct
>>
>> make -j12 && ./ffmpeg -i ~/tickets/3453/mov_with_tmcd.mov -y  -bitexact 
> -codec copy -map 0 -t 2 file.mov ; ./ffprobe -v 0 file.mov -show_packets 
> -print_format compact > /tmp/before
>>
>> --- /tmp/before	2019-12-20 23:28:04.009327038 +0100
>> +++ /tmp/after	2019-12-20 23:27:17.213326052 +0100
>> @@ -188,7 +188,7 @@
>> 
> packet|codec_type=audio|stream_index=1|pts=88320|pts_time=1.840000|dts=88320|dts_time=1.840000|duration=1024|duration_time=0.021333|convergence_duration=N/A|convergence_duration_time=N/A|size=4096|pos=408905|flags=K_
>> 
> packet|codec_type=data|stream_index=2|pts=46|pts_time=1.840000|dts=46|dts_time=1.840000|duration=1|duration_time=0.040000|convergence_duration=N/A|convergence_duration_time=N/A|size=4|pos=413001|flags=K_
>> 
> packet|codec_type=audio|stream_index=1|pts=89344|pts_time=1.861333|dts=89344|dts_time=1.861333|duration=896|duration_time=0.018667|convergence_duration=N/A|convergence_duration_time=N/A|size=3584|pos=413005|flags=K_
>> 
> -packet|codec_type=video|stream_index=0|pts=26624|pts_time=2.080000|dts=24064|dts_time=1.880000|duration=512|duration_time=0.040000|convergence_duration=N/A|convergence_duration_time=N/A|size=776|pos=416589|flags=_D
>> 
> +packet|codec_type=video|stream_index=0|pts=26624|pts_time=2.080000|dts=24064|dts_time=1.880000|duration=512|duration_time=0.040000|convergence_duration=N/A|convergence_duration_time=N/A|size=776|pos=416589|flags=__
>> 
> packet|codec_type=audio|stream_index=1|pts=90240|pts_time=1.880000|dts=90240|dts_time=1.880000|duration=1024|duration_time=0.021333|convergence_duration=N/A|convergence_duration_time=N/A|size=4096|pos=417365|flags=K_
>> 
> packet|codec_type=data|stream_index=2|pts=47|pts_time=1.880000|dts=47|dts_time=1.880000|duration=1|duration_time=0.040000|convergence_duration=N/A|convergence_duration_time=N/A|size=4|pos=421461|flags=K_
>> 
> packet|codec_type=audio|stream_index=1|pts=91264|pts_time=1.901333|dts=91264|dts_time=1.901333|duration=896|duration_time=0.018667|convergence_duration=N/A|convergence_duration_time=N/A|size=3584|pos=421465|flags=K_
>
> I would say the new behaviour is more correct here.

So, if there's no new remarks to this patch, I'd like to push e.g. 
tomorrow.

// Martin