[FFmpeg-trac] #6891(ffplay:new): FFplay: WASAPI can't initialize audio client (zeranoe's FFmpeg 3.4 MS Windows binaries)

[FFmpeg]

#6891: FFplay: WASAPI can't initialize audio client (zeranoe's FFmpeg 3.4 MS
Windows binaries)
-------------------------------------+-------------------------------------
             Reporter:  unknown      |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:  ffplay       |                  Version:
             Keywords:  ffplay       |  unspecified
  windows win32 sdl_openaudio        |               Blocked By:
  wasapi coinitialize                |  Reproduced by developer:  0
             Blocking:               |
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug:
 When I try to play an audio file with ffplay, it fails with errors such as
 this one:
 {{{
 SDL_OpenAudio (1 channels, 48000 Hz): WASAPI can't initialize audio
 client: No se ha llamado a CoInitialize.
 }}}

 How to reproduce:
 {{{
 C:\Users\Public\Documents>ffplay.exe C:\Users\Public\Documents\test.mp3
 ffplay version 3.4 Copyright (c) 2003-2017 the FFmpeg developers
   built with gcc 7.2.0 (GCC)
   configuration: --disable-static --enable-shared --enable-gpl --enable-
 version3 --enable-sdl2 --enable-bzlib --enable-fontconfig --enable-gnutls
 --enable-iconv --enable-libass --enable-libbluray --enable-libfreetype
 --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-
 libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-
 libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-
 libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma
 --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis
 --enable-cuda --enable-cuvid --enable-d3d11va --enable-nvenc --enable-
 dxva2 --enable-avisynth --enable-libmfx
   libavutil      55. 78.100 / 55. 78.100
   libavcodec     57.107.100 / 57.107.100
   libavformat    57. 83.100 / 57. 83.100
   libavdevice    57. 10.100 / 57. 10.100
   libavfilter     6.107.100 /  6.107.100
   libswscale      4.  8.100 /  4.  8.100
   libswresample   2.  9.100 /  2.  9.100
   libpostproc    54.  7.100 / 54.  7.100
 Input #0, mp3, from 'C:\Users\Public\Documents\test.mp3':  0B f=0/0
   Metadata:
     encoder         : Lavf53.32.100
   Duration: 01:00:00.26, start: 0.000000, bitrate: 128 kb/s
     Stream #0:0: Audio: mp3, 48000 Hz, stereo, s16p, 128 kb/s
 SDL_OpenAudio (2 channels, 48000 Hz): WASAPI can't initialize audio
 client: No se ha llamado a CoInitialize.

 SDL_OpenAudio (1 channels, 48000 Hz): WASAPI can't initialize audio
 client: No se ha llamado a CoInitialize.

 SDL_OpenAudio (2 channels, 44100 Hz): WASAPI can't initialize audio
 client: No se ha llamado a CoInitialize.

 SDL_OpenAudio (1 channels, 44100 Hz): WASAPI can't initialize audio
 client: No se ha llamado a CoInitialize.

 No more combinations to try, audio open failed
 Failed to open file 'C:\Users\Public\Documents\test.mp3' or configure
 filtergraph
     nan    :  0.000 fd=   0 aq=    0KB vq=    0KB sq=    0B f=0/0
 }}}

 Last working version: ffplay from ffmpeg-20170921-183fd30-win32-shared

 There is a workaround to this issue, according to this
 [https://stackoverflow.com/questions/46835811/ffplay-wasapi-cant-
 initialize-audio-client-ffmpeg-3-4-binaries question] at
 ''stackoverflow'':

 {{{
 A workaround is to specify an alternate output driver.
 Set SDL_AUDIODRIVER environment variable value to the
 driver you want to use. Under windows 7, directsound
 and winmm both solved my issue.
 }}}

 And there is a
 [https://ffmpeg.zeranoe.com/forum/viewtopic.php?t=5192#p12845 proposed
 fix] to this issue at ''ffmpeg.zeranoe.com'' forum:

 {{{
 Re: I can't run ffplay because of errors of SDL_OpenAudio

 Post by jackyxinli » Wed Nov 29, 2017 2:43 am

 I find a new method to resolve this problem, the ffplay
 not call CoInitialize according to error message. So,
 add code to call CoInitialize, ffplay can work. And the
 same time, I checked SDL2's source code, the WASAPI
 module doesn't set member ProvidesOwnCallbackThread, so
 SDL2 should call CoInitialize before open audio device.
 But no idea why ffplay gives us this error message.

 here is my modification look like.

 #ifdef _WIN32
 #include <windows.h>
 #endif

 static int audio_open(void *opaque, int64_t wanted_channel_layout, int
 wanted_nb_channels, int wanted_sample_rate, struct AudioParams
 *audio_hw_params)
 {
 ......
 #ifdef _WIN32
 CoInitialize(NULL);
 #endif
 while (!(audio_dev = SDL_OpenAudioDevice(NULL, 0, &wanted_spec, &spec,
 SDL_AUDIO_ALLOW_FREQUENCY_CHANGE | SDL_AUDIO_ALLOW_CHANNELS_CHANGE))) {
 ......
 }
 }}}

--
Ticket URL: <https://trac.ffmpeg.org/ticket/6891>
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