[FFmpeg-user] ffplay on current build does not play mkv file but on old build does.

[Moritz Barsnick]

On Tue, Mar 28, 2017 at 01:33:15 -0700, Tim Hiles wrote:
> Hi All!
> 
> I'm revisiting this issue because I've finally had time to narrow down the
> exact release where this issue first arose from so that perhaps someone who
> understands the code could maybe figure out what may have happened.
[...]
>       ffmpeg-20160926-64545dd-win32-static.zip
[...]
>       ffmpeg-20160924-1212e34-win32-static.zip
[...]
> Starting from the old release going up here is what I've discovered..
> 1. September 23 2016 at 22:11 is the last version that plays video in the
> mkv file.
> 2. September 24 2016 and September 26 2016 you'll notice that the zip
> folder size drops down to 27 M. That's because if you download those two
> zip folders you'll see that ffplay.exe was not included.
> 3. Then September 26, 2016 (later that evening) it goes back up to 41M
> because it includes ffplay.  From that point on, ffplay no longer plays
> mkv's for me, only audio.

Firstly: "It works for me(TM)." I can play that file's video with the
64bit version from Zeranoe.

Interestingly, between those two builds you mention (1212e34..64545dd),
ffplay was switched from using the SDL1 library to SDL2. (Zeranoe
probably didn't have the latter available in their build environment
for a few days, until they noticed.)[*]

> So, I'm unsure what happened at that time but that if any developers want
> to look into this, this is where I would start my investigation.

Great that you were able to track that down. I don't know how to debug
the SDL display device though.

Does this command show you something on your screen, i.e. does the sdl2
output device work?

$ ffmpeg -re -f lavfi -i testsrc2=s=1366x768:r=30,format=yuv420p -f sdl2 foo

Moritz

[*] (Yes, the commit was created on Feb 23 2106, but it didn't get into
     git master until that point in September.)
commit 9c5fab5ed421da4e55cafcbff0482e1ad926c27b
Author: Marton Balint <cus at passwd.hu>
Date:   Tue Feb 23 20:43:41 2016 +0000

    ffplay: add SDL2 support

    This commit also drops SDL1 support for ffplay.

    Tested-by: James Almer <jamrial at gmail.com> (Windows, mingw-w64)
    Signed-off-by: Josh de Kock <josh at itanimul.li>

M       Changelog
M       configure
M       ffplay.c