On 07. 02. 24 16:34, Pavel Hofman wrote:
But honestly I still do not understand what it actually does and what is
the goal of snd_pcm_plug_slave_format().
Without that I cannot modify snd_pcm_plug_slave_format() correctly to
incorporate support for IEC958.
I believe you're looking to a wrong place. Here's incomplete code:
==========
diff --git a/configure.ac b/configure.ac
index 7a152a4a..3f238302 100644
--- a/configure.ac
+++ b/configure.ac
@@ -642,6 +642,9 @@ fi
if test "$build_pcm_alaw" = "yes"; then
AC_DEFINE([BUILD_PCM_PLUGIN_ALAW], "1", [Build PCM alaw plugin])
fi
+if test "$build_pcm_iec958" = "yes"; then
+ AC_DEFINE([BUILD_PCM_PLUGIN_IEC958], "1", [Build PCM iec958 plugin])
+fi
if test "$build_pcm_mmap_emul" = "yes"; then
AC_DEFINE([BUILD_PCM_PLUGIN_MMAP_EMUL], "1", [Build PCM mmap-emul plugin])
fi
diff --git a/include/pcm_plugin.h b/include/pcm_plugin.h
index 2d014394..f3e8f3b5 100644
--- a/include/pcm_plugin.h
+++ b/include/pcm_plugin.h
@@ -133,6 +133,19 @@ int _snd_pcm_adpcm_open(snd_pcm_t **pcmp, const char *name,
snd_config_t *root, snd_config_t *conf,
snd_pcm_stream_t stream, int mode);
+/*
+ * IEC958 subframe conversion plugin
+ */
+int snd_pcm_iec958_open(snd_pcm_t **pcmp, const char *name,
+ snd_pcm_format_t sformat, snd_pcm_t *slave,
+ int close_slave,
+ const unsigned char *status_bits,
+ const unsigned char *preamble_vals,
+ int hdmi_mode);
+int _snd_pcm_iec958_open(snd_pcm_t **pcmp, const char *name,
+ snd_config_t *root, snd_config_t *conf,
+ snd_pcm_stream_t stream, int mode);
+
/*
* Route plugin for linear formats
*/
diff --git a/src/pcm/pcm_plug.c b/src/pcm/pcm_plug.c
index e5a3a189..287fb9f9 100644
--- a/src/pcm/pcm_plug.c
+++ b/src/pcm/pcm_plug.c
@@ -186,7 +186,8 @@ static const snd_pcm_format_t linear_preferred_formats[] = {
#if defined(BUILD_PCM_PLUGIN_MULAW) || \
defined(BUILD_PCM_PLUGIN_ALAW) || \
- defined(BUILD_PCM_PLUGIN_ADPCM)
+ defined(BUILD_PCM_PLUGIN_ADPCM) || \
+ defined(BUILD_PCM_PLUGIN_IEC958)
#define BUILD_PCM_NONLINEAR
#endif
@@ -201,6 +202,10 @@ static const snd_pcm_format_t nonlinear_preferred_formats[] = {
#ifdef BUILD_PCM_PLUGIN_ADPCM
SND_PCM_FORMAT_IMA_ADPCM,
#endif
+#ifdef BUILD_PCM_PLUGIN_IEC958
+ SND_PCM_FORMAT_IEC958_SUBFRAME_LE,
+ SND_PCM_FORMAT_IEC958_SUBFRAME_BE,
+#endif
};
#endif
@@ -490,6 +495,18 @@ static int snd_pcm_plug_change_channels(snd_pcm_t *pcm, snd_pcm_t **new, snd_pcm
}
#endif
+#ifdef BUILD_PCM_PLUGIN_IEC958
+static int iec958_open(snd_pcm_t **pcmp, const char *name,
+ snd_pcm_format_t sformat, snd_pcm_t *slave,
+ int close_slave)
+{
+ unsigned char preamble_vals[3] = {
+ 0x08, 0x02, 0x04 /* Z, X, Y */
+ };
+ return snd_pcm_iec958_open(pcmp, name, sformat, slave, close_slave, NULL, preamble_vals, 0);
+}
+#endif
+
static int snd_pcm_plug_change_format(snd_pcm_t *pcm, snd_pcm_t **new, snd_pcm_plug_params_t *clt, snd_pcm_plug_params_t *slv)
{
snd_pcm_plug_t *plug = pcm->private_data;
@@ -526,6 +543,12 @@ static int snd_pcm_plug_change_format(snd_pcm_t *pcm, snd_pcm_t **new, snd_pcm_p
case SND_PCM_FORMAT_IMA_ADPCM:
f = snd_pcm_adpcm_open;
break;
+#endif
+#ifdef BUILD_PCM_PLUGIN_IEC958
+ case SND_PCM_FORMAT_IEC958_SUBFRAME_LE:
+ case SND_PCM_FORMAT_IEC958_SUBFRAME_BE:
+ f = iec958_open;
+ break;
#endif
default:
#ifdef BUILD_PCM_PLUGIN_LFLOAT
@@ -566,6 +589,12 @@ static int snd_pcm_plug_change_format(snd_pcm_t *pcm, snd_pcm_t **new, snd_pcm_p
case SND_PCM_FORMAT_IMA_ADPCM:
f = snd_pcm_adpcm_open;
break;
+#endif
+#ifdef BUILD_PCM_PLUGIN_IEC958
+ case SND_PCM_FORMAT_IEC958_SUBFRAME_LE:
+ case SND_PCM_FORMAT_IEC958_SUBFRAME_BE:
+ f = iec958_open;
+ break;
#endif
default:
return -EINVAL;
=========
Test:
========= ~/.asoundrc
pcm.test123 {
type plug
slave {
pcm null
format IEC958_SUBFRAME_LE
}
}
=========
$ LD_PRELOAD=~/alsa/alsa-lib/src/.libs/libasound.so aplay -v -D test123 /dev/zero
Playing raw data '/dev/zero' : Unsigned 8 bit, Rate 8000 Hz, Mono
Plug PCM: IEC958 subframe conversion PCM (IEC958_SUBFRAME_LE)
Its setup is:
stream : PLAYBACK
access : RW_INTERLEAVED
format : U8
subformat : STD
channels : 1
rate : 8000
exact rate : 8000 (8000/1)
msbits : 8
buffer_size : 4000
period_size : 1000
period_time : 125000
tstamp_mode : ENABLE
tstamp_type : GETTIMEOFDAY
period_step : 1
avail_min : 1000
period_event : 0
start_threshold : 4000
stop_threshold : 4000
silence_threshold: 0
silence_size : 0
boundary : 9007199254740992000
Slave: Null PCM
Its setup is:
stream : PLAYBACK
access : MMAP_INTERLEAVED
format : IEC958_SUBFRAME_LE
subformat : STD
channels : 1
rate : 8000
exact rate : 8000 (8000/1)
msbits : 32
buffer_size : 4000
period_size : 1000
period_time : 125000
tstamp_mode : ENABLE
tstamp_type : GETTIMEOFDAY
period_step : 1
avail_min : 1000
period_event : 0
start_threshold : 4000
stop_threshold : 4000
silence_threshold: 0
silence_size : 0
boundary : 9007199254740992000
Jaroslav
--
Jaroslav Kysela <perex@xxxxxxxx>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.
