[FFmpeg-devel] [PATCH] lavf/utils: update default wrap-around reference while iterating streams

[Carl Eugen Hoyos]

2019-02-07 8:18 GMT+01:00, Jan Ekström <jeebjp at gmail.com>:
> On Thu, Feb 7, 2019, 02:22 Carl Eugen Hoyos <ceffmpeg at gmail.com wrote:
>
>> 2019-02-07 0:57 GMT+01:00, Jan Ekström <jeebjp at gmail.com>:
>> > From: Masaki Tanaka <maki.rxrz at gmail.com>
>> >
>> > Seems to fix mistaken cases of discontinuity handling in MPEG-TS
>> > when program structure changes.
>> >
>> > Additional changes to patch from its original state by Jan Ekström.
>> > ---
>> >
>> > Had been meaning to post this for comments/discussion for a while, as
>> > this seems to make timestamps continuously rising in at least one of
>> > my samples where the program structure changes mid-stream.
>> >
>> > The original version of this patch can be found at:
>> >
>> https://github.com/jeeb/ffmpeg/commit/6117366eaadbaf48bbd88eb2a353dfc852ff3400
>> >
>> > The sample for which this helped is available at:
>> > https://kuroko.fushizen.eu/samples/pid_switch_sample.ts
>> >
>> > The difference of timestamps received from libavformat can be seen with:
>> >
>> https://kuroko.fushizen.eu/screenshots/ffmpeg/blue_vanilla-orange_patched.png
>>
>> Am I correct that even with this patch, the sample cannot
>> be decoded / played correctly with FFmpeg / FFplay?
>>
>> No opinion about the patch, just curious, Carl Eugen
>>
>
> Yes, ffmpeg.c at least is static in its stream selection (and probably so
> is ffplay.c) so they would ignore the other video stream either before or
> after the switch depending on how much you probe and if you do manual
> stream selection.
>
> That said, this is a simple sample (no alternatives, just a clear cut
> switch) so -merge_pmt_versions 1 should work for it to get both the sd and
> hd parts decoded. This attempts to re-use a previous AVStream when a stream
> is removed.

Thank you, I forgot about this switch: The original timestamp issue
is not reproducible with -merge_pmt_versions, right?

Carl Eugen
(who hopes you can use fieldmatch to watch this...)