From 5a0926c23fa915f26f66f688e9030ce39fea1e35 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Volker=20R=C3=BCmelin?= Date: Sun, 10 Jan 2021 11:02:19 +0100 Subject: [PATCH] sdlaudio: add -audiodev sdl,out.buffer-count option MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently there is a crackling noise with SDL2 audio playback. Commit bcf19777df: "audio/sdlaudio: Allow audio playback with SDL2" already mentioned the crackling noise. Add an out.buffer-count option to give users a chance to select sane settings for glitch free audio playback. The idea was taken from the coreaudio backend. The in.buffer-count option will be used with one of the next patches. Signed-off-by: Volker Rümelin Acked-by: Markus Armbruster Message-id: 9315afe5-5958-c0b4-ea1e-14769511a9d5@t-online.de Message-Id: <20210110100239.27588-3-vr_qemu@t-online.de> Signed-off-by: Gerd Hoffmann --- audio/audio.c | 2 +- audio/audio_legacy.c | 3 ++- audio/audio_template.h | 2 +- audio/sdlaudio.c | 11 +++++++++-- qapi/audio.json | 33 ++++++++++++++++++++++++++++++++- qemu-options.hx | 8 +++++++- 6 files changed, 52 insertions(+), 7 deletions(-) diff --git a/audio/audio.c b/audio/audio.c index b48471bb3f..d048d26283 100644 --- a/audio/audio.c +++ b/audio/audio.c @@ -2003,7 +2003,7 @@ void audio_create_pdos(Audiodev *dev) CASE(JACK, jack, Jack); CASE(OSS, oss, Oss); CASE(PA, pa, Pa); - CASE(SDL, sdl, ); + CASE(SDL, sdl, Sdl); CASE(SPICE, spice, ); CASE(WAV, wav, ); diff --git a/audio/audio_legacy.c b/audio/audio_legacy.c index ffdbd0bcce..0fe827b057 100644 --- a/audio/audio_legacy.c +++ b/audio/audio_legacy.c @@ -286,7 +286,8 @@ static void handle_sdl(Audiodev *dev) { /* SDL is output only */ get_samples_to_usecs("QEMU_SDL_SAMPLES", &dev->u.sdl.out->buffer_length, - &dev->u.sdl.out->has_buffer_length, dev->u.sdl.out); + &dev->u.sdl.out->has_buffer_length, + qapi_AudiodevSdlPerDirectionOptions_base(dev->u.sdl.out)); } /* wav */ diff --git a/audio/audio_template.h b/audio/audio_template.h index 8dd48ce14e..434df5d5e7 100644 --- a/audio/audio_template.h +++ b/audio/audio_template.h @@ -337,7 +337,7 @@ AudiodevPerDirectionOptions *glue(audio_get_pdo_, TYPE)(Audiodev *dev) case AUDIODEV_DRIVER_PA: return qapi_AudiodevPaPerDirectionOptions_base(dev->u.pa.TYPE); case AUDIODEV_DRIVER_SDL: - return dev->u.sdl.TYPE; + return qapi_AudiodevSdlPerDirectionOptions_base(dev->u.sdl.TYPE); case AUDIODEV_DRIVER_SPICE: return dev->u.spice.TYPE; case AUDIODEV_DRIVER_WAV: diff --git a/audio/sdlaudio.c b/audio/sdlaudio.c index 00cd12ba66..431bfcfddd 100644 --- a/audio/sdlaudio.c +++ b/audio/sdlaudio.c @@ -276,12 +276,18 @@ static int sdl_init_out(HWVoiceOut *hw, struct audsettings *as, int endianness; int err; AudioFormat effective_fmt; + AudiodevSdlPerDirectionOptions *spdo = s->dev->u.sdl.out; struct audsettings obt_as; req.freq = as->freq; req.format = aud_to_sdlfmt (as->fmt); req.channels = as->nchannels; - req.samples = audio_buffer_samples(s->dev->u.sdl.out, as, 11610); + /* + * This is wrong. SDL samples are QEMU frames. The buffer size will be + * the requested buffer size multiplied by the number of channels. + */ + req.samples = audio_buffer_samples( + qapi_AudiodevSdlPerDirectionOptions_base(spdo), as, 11610); req.callback = sdl_callback; req.userdata = sdl; @@ -301,7 +307,8 @@ static int sdl_init_out(HWVoiceOut *hw, struct audsettings *as, obt_as.endianness = endianness; audio_pcm_init_info (&hw->info, &obt_as); - hw->samples = obt.samples; + hw->samples = (spdo->has_buffer_count ? spdo->buffer_count : 4) * + obt.samples; s->initialized = 1; s->exit = 0; diff --git a/qapi/audio.json b/qapi/audio.json index 072ed79def..9cba0df8a4 100644 --- a/qapi/audio.json +++ b/qapi/audio.json @@ -301,6 +301,37 @@ '*out': 'AudiodevPaPerDirectionOptions', '*server': 'str' } } +## +# @AudiodevSdlPerDirectionOptions: +# +# Options of the SDL audio backend that are used for both playback and +# recording. +# +# @buffer-count: number of buffers (default 4) +# +# Since: 6.0 +## +{ 'struct': 'AudiodevSdlPerDirectionOptions', + 'base': 'AudiodevPerDirectionOptions', + 'data': { + '*buffer-count': 'uint32' } } + +## +# @AudiodevSdlOptions: +# +# Options of the SDL audio backend. +# +# @in: options of the recording stream +# +# @out: options of the playback stream +# +# Since: 6.0 +## +{ 'struct': 'AudiodevSdlOptions', + 'data': { + '*in': 'AudiodevSdlPerDirectionOptions', + '*out': 'AudiodevSdlPerDirectionOptions' } } + ## # @AudiodevWavOptions: # @@ -385,6 +416,6 @@ 'jack': 'AudiodevJackOptions', 'oss': 'AudiodevOssOptions', 'pa': 'AudiodevPaOptions', - 'sdl': 'AudiodevGenericOptions', + 'sdl': 'AudiodevSdlOptions', 'spice': 'AudiodevGenericOptions', 'wav': 'AudiodevWavOptions' } } diff --git a/qemu-options.hx b/qemu-options.hx index 1698a0c751..4e02e9bd76 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -588,6 +588,7 @@ DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev, #endif #ifdef CONFIG_AUDIO_SDL "-audiodev sdl,id=id[,prop[=value][,...]]\n" + " in|out.buffer-count= number of buffers\n" #endif #ifdef CONFIG_SPICE "-audiodev spice,id=id[,prop[=value][,...]]\n" @@ -745,7 +746,12 @@ SRST ``-audiodev sdl,id=id[,prop[=value][,...]]`` Creates a backend using SDL. This backend is available on most systems, but you should use your platform's native backend if - possible. This backend has no backend specific properties. + possible. + + SDL specific options are: + + ``in|out.buffer-count=count`` + Sets the count of the buffers. ``-audiodev spice,id=id[,prop[=value][,...]]`` Creates a backend that sends audio through SPICE. This backend