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[patch] patch

SDL_ALSA_MIN.patch (text/plain), 4.24 KB, created by Anthony Pesch on 2019-07-06 03:37:07 UTC

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Creator: Anthony Pesch

Created: 2019-07-06 03:37:07 UTC

Size: 4.24 KB

patch

obsolete

>commit 89b350161a1027e0a3a1b677de2ebf9e9dbe54f7
>Author: Anthony Pesch <inolen@gmail.com>
>Date:   Fri Jul 5 20:49:34 2019 -0400
>
>    alsa: avoid configuring hardware parameters with only a single period
>    
>    The previous code first configured the period size using snd_pcm_hw_par-
>    ams_set_period_size_near. Then, it further narrowed the configuration
>    space by calling snd_pcm_hw_params_set_buffer_size_near using a buffer
>    size of 2 times the _requested_ period size in order to try and get a
>    configuration with only 2 periods. If the configured period size was
>    larger than the requested size, the second call could inadvertently
>    narrow the configuration space to contain only a single period.
>    
>    Rather than fixing the call to snd_pcm_hw_params_set_buffer_size_near
>    to use a size of 2 times the configured period size, the code has been
>    changed to use snd_pcm_hw_params_set_periods_min in order to more
>    clearly explain the intent.
>
>diff --git a/deps/sdl2/src/audio/alsa/SDL_alsa_audio.c b/deps/sdl2/src/audio/alsa/SDL_alsa_audio.c
>index 9364fc1b8..b65de7889 100644
>--- a/deps/sdl2/src/audio/alsa/SDL_alsa_audio.c
>+++ b/deps/sdl2/src/audio/alsa/SDL_alsa_audio.c
>@@ -72,7 +72,9 @@ static int (*ALSA_snd_pcm_hw_params_set_period_size_near)
>   (snd_pcm_t *, snd_pcm_hw_params_t *, snd_pcm_uframes_t *, int *);
> static int (*ALSA_snd_pcm_hw_params_get_period_size)
>   (const snd_pcm_hw_params_t *, snd_pcm_uframes_t *, int *);
>-static int (*ALSA_snd_pcm_hw_params_set_periods_near)
>+static int (*ALSA_snd_pcm_hw_params_set_periods_min)
>+  (snd_pcm_t *, snd_pcm_hw_params_t *, unsigned int *, int *);
>+static int (*ALSA_snd_pcm_hw_params_set_periods_first)
>   (snd_pcm_t *, snd_pcm_hw_params_t *, unsigned int *, int *);
> static int (*ALSA_snd_pcm_hw_params_get_periods)
>   (const snd_pcm_hw_params_t *, unsigned int *, int *);
>@@ -148,7 +150,8 @@ load_alsa_syms(void)
>     SDL_ALSA_SYM(snd_pcm_hw_params_set_rate_near);
>     SDL_ALSA_SYM(snd_pcm_hw_params_set_period_size_near);
>     SDL_ALSA_SYM(snd_pcm_hw_params_get_period_size);
>-    SDL_ALSA_SYM(snd_pcm_hw_params_set_periods_near);
>+    SDL_ALSA_SYM(snd_pcm_hw_params_set_periods_min);
>+    SDL_ALSA_SYM(snd_pcm_hw_params_set_periods_first);
>     SDL_ALSA_SYM(snd_pcm_hw_params_get_periods);
>     SDL_ALSA_SYM(snd_pcm_hw_params_set_buffer_size_near);
>     SDL_ALSA_SYM(snd_pcm_hw_params_get_buffer_size);
>@@ -462,14 +465,14 @@ ALSA_set_buffer_size(_THIS, snd_pcm_hw_params_t *params)
> {
>     int status;
>     snd_pcm_hw_params_t *hwparams;
>-    snd_pcm_uframes_t bufsize;
>     snd_pcm_uframes_t persize;
>+    unsigned int periods;
> 
>     /* Copy the hardware parameters for this setup */
>     snd_pcm_hw_params_alloca(&hwparams);
>     ALSA_snd_pcm_hw_params_copy(hwparams, params);
> 
>-    /* Prioritize matching the period size to the requested buffer size */
>+    /* Attempt to match the period size to the requested buffer size */
>     persize = this->spec.samples;
>     status = ALSA_snd_pcm_hw_params_set_period_size_near(
>                 this->hidden->pcm_handle, hwparams, &persize, NULL);
>@@ -477,10 +480,16 @@ ALSA_set_buffer_size(_THIS, snd_pcm_hw_params_t *params)
>         return(-1);
>     }
> 
>-    /* Next try to restrict the parameters to having only two periods */
>-    bufsize = this->spec.samples * 2;
>-    status = ALSA_snd_pcm_hw_params_set_buffer_size_near(
>-                    this->hidden->pcm_handle, hwparams, &bufsize);
>+    /* Need to at least double buffer */
>+    periods = 2;
>+    status = ALSA_snd_pcm_hw_params_set_periods_min(
>+                this->hidden->pcm_handle, hwparams, &periods, NULL);
>+    if ( status < 0 ) {
>+        return(-1);
>+    }
>+
>+    status = ALSA_snd_pcm_hw_params_set_periods_first(
>+                this->hidden->pcm_handle, hwparams, &periods, NULL);
>     if ( status < 0 ) {
>         return(-1);
>     }
>@@ -495,9 +504,9 @@ ALSA_set_buffer_size(_THIS, snd_pcm_hw_params_t *params)
> 
>     /* This is useful for debugging */
>     if ( SDL_getenv("SDL_AUDIO_ALSA_DEBUG") ) {
>-        unsigned int periods = 0;
>+        snd_pcm_uframes_t bufsize;
> 
>-        ALSA_snd_pcm_hw_params_get_periods(hwparams, &periods, NULL);
>+        ALSA_snd_pcm_hw_params_get_buffer_size(hwparams, &bufsize);
> 
>         fprintf(stderr,
>             "ALSA: period size = %ld, periods = %u, buffer size = %lu\n",

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We are currently migrating Bugzilla to GitHub issues.Any changes made to the bug tracker now will be lost, so please do not post new bugs or make changes to them.When we're done, all bug URLs will redirect to their equivalent location on the new bug tracker.

We are currently migrating Bugzilla to GitHub issues.
Any changes made to the bug tracker now will be lost, so please do not post new bugs or make changes to them.
When we're done, all bug URLs will redirect to their equivalent location on the new bug tracker.