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pcm: Fix forward/rewind support in iec958 plugin

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When forwarding or rewinding, the frame counter was not updated. This
could result in corrupted channel status words or misplaced Z-type
preamble.

Signed-off-by: Alexander E. Patrakov <patrakov@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Alexander E. Patrakov 2014-04-24 20:40:06 +06:00 • committed by Takashi Iwai
parent 351870fd2d
commit 80a43f23db
3 changed files with 44 additions and 3 deletions
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37
src/pcm/pcm_iec958.c
View file

@ -62,6 +62,7 @@ struct snd_pcm_iec958 {
unsigned char status[24];
unsigned int byteswap;
unsigned char preamble[3]; /* B/M/W or Z/X/Y */
snd_pcm_fast_ops_t fops;
};
enum { PREAMBLE_Z, PREAMBLE_X, PREAMBLE_Y };
@ -416,6 +417,35 @@ static void snd_pcm_iec958_dump(snd_pcm_t *pcm, snd_output_t *out)
snd_pcm_dump(iec->plug.gen.slave, out);
}
static snd_pcm_sframes_t snd_pcm_iec958_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
{
unsigned int counter_decrement;
snd_pcm_iec958_t *iec = pcm->private_data;
snd_pcm_sframes_t result = snd_pcm_plugin_rewind(pcm, frames);
if (result <= 0)
return result;
counter_decrement = result % 192;
iec->counter += 192 - counter_decrement;
iec->counter %= 192;
return result;
}
static snd_pcm_sframes_t snd_pcm_iec958_forward(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
{
unsigned int counter_increment;
snd_pcm_iec958_t *iec = pcm->private_data;
snd_pcm_sframes_t result = snd_pcm_plugin_rewind(pcm, frames);
if (result <= 0)
return result;
counter_increment = result % 192;
iec->counter += counter_increment;
iec->counter %= 192;
return result;
}
static const snd_pcm_ops_t snd_pcm_iec958_ops = {
.close = snd_pcm_generic_close,
.info = snd_pcm_generic_info,
@ -495,7 +525,12 @@ int snd_pcm_iec958_open(snd_pcm_t **pcmp, const char *name, snd_pcm_format_t sfo
return err;
}
pcm->ops = &snd_pcm_iec958_ops;
pcm->fast_ops = &snd_pcm_plugin_fast_ops;
iec->fops = snd_pcm_plugin_fast_ops;
iec->fops.rewind = snd_pcm_iec958_rewind;
iec->fops.forward = snd_pcm_iec958_forward;
pcm->fast_ops = &iec->fops;
pcm->private_data = iec;
pcm->poll_fd = slave->poll_fd;
pcm->poll_events = slave->poll_events;

4
src/pcm/pcm_plugin.c
View file

@ -201,7 +201,7 @@ static snd_pcm_sframes_t snd_pcm_plugin_rewindable(snd_pcm_t *pcm)
return snd_pcm_mmap_hw_avail(pcm);
}
static snd_pcm_sframes_t snd_pcm_plugin_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
snd_pcm_sframes_t snd_pcm_plugin_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
{
snd_pcm_plugin_t *plugin = pcm->private_data;
snd_pcm_sframes_t n = snd_pcm_mmap_hw_avail(pcm);
@ -229,7 +229,7 @@ static snd_pcm_sframes_t snd_pcm_plugin_forwardable(snd_pcm_t *pcm)
return snd_pcm_mmap_avail(pcm);
}
static snd_pcm_sframes_t snd_pcm_plugin_forward(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
snd_pcm_sframes_t snd_pcm_plugin_forward(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
{
snd_pcm_plugin_t *plugin = pcm->private_data;
snd_pcm_sframes_t n = snd_pcm_mmap_avail(pcm);

6
src/pcm/pcm_plugin.h
View file

@ -58,8 +58,14 @@ typedef struct {
snd1_pcm_plugin_undo_read_generic
#define snd_pcm_plugin_undo_write_generic \
snd1_pcm_plugin_undo_write_generic
#define snd_pcm_plugin_rewind \
snd1_pcm_plugin_rewind
#define snd_pcm_plugin_forward \
snd1_pcm_plugin_forward
void snd_pcm_plugin_init(snd_pcm_plugin_t *plugin);
snd_pcm_sframes_t snd_pcm_plugin_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t frames);
snd_pcm_sframes_t snd_pcm_plugin_forward(snd_pcm_t *pcm, snd_pcm_uframes_t frames);
extern const snd_pcm_fast_ops_t snd_pcm_plugin_fast_ops;