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output/alsa: use pcm_export to pack 24 bit samples

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This commit is contained in:
Max Kellermann
2012-03-21 23:59:31 +01:00
parent 43774455cc
commit 208a96b211
1 changed files with 48 additions and 15 deletions
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63
src/output/alsa_output_plugin.c
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@@ -211,6 +211,7 @@ get_bitformat(enum sample_format sample_format)
case SAMPLE_FORMAT_UNDEFINED:
case SAMPLE_FORMAT_DSD:
case SAMPLE_FORMAT_DSD_OVER_USB:
case SAMPLE_FORMAT_S24:
return SND_PCM_FORMAT_UNKNOWN;
case SAMPLE_FORMAT_S8:
@@ -222,11 +223,6 @@ get_bitformat(enum sample_format sample_format)
case SAMPLE_FORMAT_S24_P32:
return SND_PCM_FORMAT_S24;
case SAMPLE_FORMAT_S24:
return G_BYTE_ORDER == G_BIG_ENDIAN
? SND_PCM_FORMAT_S24_3BE
: SND_PCM_FORMAT_S24_3LE;
case SAMPLE_FORMAT_S32:
return SND_PCM_FORMAT_S32;
@@ -259,6 +255,43 @@ byteswap_bitformat(snd_pcm_format_t fmt)
}
}
static snd_pcm_format_t
alsa_to_packed_format(snd_pcm_format_t fmt)
{
switch (fmt) {
case SND_PCM_FORMAT_S24_LE:
return SND_PCM_FORMAT_S24_3LE;
case SND_PCM_FORMAT_S24_BE:
return SND_PCM_FORMAT_S24_3BE;
default:
return SND_PCM_FORMAT_UNKNOWN;
}
}
static int
alsa_try_format_or_packed(snd_pcm_t *pcm, snd_pcm_hw_params_t *hwparams,
snd_pcm_format_t fmt, bool *packed_r)
{
int err = snd_pcm_hw_params_set_format(pcm, hwparams, fmt);
if (err == 0)
*packed_r = false;
if (err != -EINVAL)
return err;
fmt = alsa_to_packed_format(fmt);
if (fmt == SND_PCM_FORMAT_UNKNOWN)
return -EINVAL;
err = snd_pcm_hw_params_set_format(pcm, hwparams, fmt);
if (err == 0)
*packed_r = true;
return err;
}
/**
* Attempts to configure the specified sample format, and tries the
* reversed host byte order if was not supported.
@@ -266,13 +299,14 @@ byteswap_bitformat(snd_pcm_format_t fmt)
static int
alsa_output_try_format(snd_pcm_t *pcm, snd_pcm_hw_params_t *hwparams,
enum sample_format sample_format,
bool *reverse_endian_r)
bool *packed_r, bool *reverse_endian_r)
{
snd_pcm_format_t alsa_format = get_bitformat(sample_format);
if (alsa_format == SND_PCM_FORMAT_UNKNOWN)
return -EINVAL;
int err = snd_pcm_hw_params_set_format(pcm, hwparams, alsa_format);
int err = alsa_try_format_or_packed(pcm, hwparams, alsa_format,
packed_r);
if (err == 0)
*reverse_endian_r = false;
@@ -283,7 +317,7 @@ alsa_output_try_format(snd_pcm_t *pcm, snd_pcm_hw_params_t *hwparams,
if (alsa_format == SND_PCM_FORMAT_UNKNOWN)
return -EINVAL;
err = snd_pcm_hw_params_set_format(pcm, hwparams, alsa_format);
err = alsa_try_format_or_packed(pcm, hwparams, alsa_format, packed_r);
if (err == 0)
*reverse_endian_r = true;
@@ -296,19 +330,18 @@ alsa_output_try_format(snd_pcm_t *pcm, snd_pcm_hw_params_t *hwparams,
static int
alsa_output_setup_format(snd_pcm_t *pcm, snd_pcm_hw_params_t *hwparams,
struct audio_format *audio_format,
bool *reverse_endian_r)
bool *packed_r, bool *reverse_endian_r)
{
/* try the input format first */
int err = alsa_output_try_format(pcm, hwparams, audio_format->format,
reverse_endian_r);
packed_r, reverse_endian_r);
/* if unsupported by the hardware, try other formats */
static const enum sample_format probe_formats[] = {
SAMPLE_FORMAT_S24_P32,
SAMPLE_FORMAT_S32,
SAMPLE_FORMAT_S24,
SAMPLE_FORMAT_S16,
SAMPLE_FORMAT_S8,
SAMPLE_FORMAT_UNDEFINED,
@@ -322,7 +355,7 @@ alsa_output_setup_format(snd_pcm_t *pcm, snd_pcm_hw_params_t *hwparams,
continue;
err = alsa_output_try_format(pcm, hwparams, mpd_format,
reverse_endian_r);
packed_r, reverse_endian_r);
if (err == 0)
audio_format->format = mpd_format;
}
@@ -380,9 +413,9 @@ configure_hw:
ad->writei = snd_pcm_writei;
}
bool reverse_endian;
bool packed, reverse_endian;
err = alsa_output_setup_format(ad->pcm, hwparams, audio_format,
&reverse_endian);
&packed, &reverse_endian);
if (err < 0) {
g_set_error(error, alsa_output_quark(), err,
"ALSA device \"%s\" does not support format %s: %s",
@@ -525,7 +558,7 @@ configure_hw:
ad->period_position = 0;
pcm_export_open(&ad->export, audio_format->format,
false, reverse_endian);
packed, reverse_endian);
return true;