diff options
| author | Solomon Peachy <pizza@shaftnet.org> | 2020-10-02 07:27:46 -0400 |
|---|---|---|
| committer | Solomon Peachy <pizza@shaftnet.org> | 2020-10-02 09:50:38 -0400 |
| commit | b0e1b245b471f2c71d7b74ce882fbaa318e3ab91 (patch) | |
| tree | f8ddb9c95cce03a0e53501f873b5363f5b0488e8 | |
| parent | 90af40e90c13eb5d6c9d6fa05bc2d1ca64fcdd0c (diff) | |
| download | rockbox-b0e1b24.tar.gz rockbox-b0e1b24.zip | |
alsa: Use larger playback buffers for higher bitrates
(existing ones apply up to 48KHz, scale up linearly to 192KHz)
Change-Id: Iac32d49b8073b63a5d40fd21f41437e6051cb8de
| -rw-r--r-- | firmware/target/hosted/pcm-alsa.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/firmware/target/hosted/pcm-alsa.c b/firmware/target/hosted/pcm-alsa.c index f33b42429c..c7df99e23d 100644 --- a/firmware/target/hosted/pcm-alsa.c +++ b/firmware/target/hosted/pcm-alsa.c @@ -81,9 +81,9 @@ static unsigned int sample_rate = 0; static unsigned int real_sample_rate = 0; static snd_pcm_t *handle = NULL; -static snd_pcm_sframes_t buffer_size = MIX_FRAME_SAMPLES * 32; /* ~16k */ -static snd_pcm_sframes_t period_size = MIX_FRAME_SAMPLES * 4; /* ~4k */ -static sample_t *frames; +static snd_pcm_sframes_t buffer_size; +static snd_pcm_sframes_t period_size; +static sample_t *frames = NULL; static const void *pcm_data = 0; static size_t pcm_size = 0; @@ -103,6 +103,18 @@ static int set_hwparams(snd_pcm_t *handle) snd_pcm_hw_params_t *params; snd_pcm_hw_params_malloc(¶ms); + /* Size playback buffers based on sample rate */ + if (pcm_sampr > SAMPR_96) { + buffer_size = MIX_FRAME_SAMPLES * 32 * 4; /* ~64k */ + period_size = MIX_FRAME_SAMPLES * 4 * 4; /* ~16k */ + } else if (pcm_sampr > SAMPR_48) { + buffer_size = MIX_FRAME_SAMPLES * 32 * 2; /* ~32k */ + period_size = MIX_FRAME_SAMPLES * 4 * 2; /* ~8k */ + } else { + buffer_size = MIX_FRAME_SAMPLES * 32; /* ~16k */ + period_size = MIX_FRAME_SAMPLES * 4; /* ~4k */ + } + /* choose all parameters */ err = snd_pcm_hw_params_any(handle, params); if (err < 0) @@ -195,7 +207,7 @@ static int set_swparams(snd_pcm_t *handle) printf("Unable to determine current swparams for playback: %s\n", snd_strerror(err)); goto error; } - /* start the transfer when the buffer is haalmost full */ + /* start the transfer when the buffer is half full */ err = snd_pcm_sw_params_set_start_threshold(handle, swparams, buffer_size / 2); if (err < 0) { |