File 0010-PCM-Implement-snd_pcm_query_chmaps_from_hw.patch of Package alsa
From 01dc0e6825b5620510faaefaef40ff8cfb692b6e Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Fri, 7 Sep 2012 14:15:04 +0200
Subject: [PATCH 10/30] PCM: Implement snd_pcm_query_chmaps_from_hw()
This is a function similar like snd_pcm_query_chmaps() but performs
the query without a PCM handle. The card, device and substream
numbers are passed as well as stream direction.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
include/pcm.h | 3 +
src/pcm/pcm_hw.c | 117 +++++++++++++++++++++++++++++++++++--------------------
2 files changed, 79 insertions(+), 41 deletions(-)
--- a/include/pcm.h
+++ b/include/pcm.h
@@ -526,6 +526,9 @@ typedef struct snd_pcm_chmap_query {
snd_pcm_chmap_query_t **snd_pcm_query_chmaps(snd_pcm_t *pcm);
+snd_pcm_chmap_query_t **snd_pcm_query_chmaps_from_hw(int card, int dev,
+ int subdev,
+ snd_pcm_stream_t stream);
void snd_pcm_free_chmaps(snd_pcm_chmap_query_t **maps);
snd_pcm_chmap_t *snd_pcm_get_chmap(snd_pcm_t *pcm);
int snd_pcm_set_chmap(snd_pcm_t *pcm, const snd_pcm_chmap_t *map);
--- a/src/pcm/pcm_hw.c
+++ b/src/pcm/pcm_hw.c
@@ -1006,80 +1006,82 @@ static int snd_pcm_hw_htimestamp(snd_pcm
return 0;
}
-static void fill_chmap_ctl_id(snd_pcm_t *pcm, snd_ctl_elem_id_t *id)
+static void __fill_chmap_ctl_id(snd_ctl_elem_id_t *id, int dev, int subdev,
+ int stream)
{
- snd_pcm_hw_t *hw = pcm->private_data;
snd_ctl_elem_id_set_interface(id, SND_CTL_ELEM_IFACE_PCM);
- if (pcm->stream == SND_PCM_STREAM_PLAYBACK)
+ if (stream == SND_PCM_STREAM_PLAYBACK)
snd_ctl_elem_id_set_name(id, "Playback Channel Map");
else
snd_ctl_elem_id_set_name(id, "Capture Channel Map");
- snd_ctl_elem_id_set_device(id, hw->device);
- snd_ctl_elem_id_set_index(id, hw->subdevice);
-}
-
-static int is_chmap_type(int type)
-{
- return (type >= SND_CTL_TLVT_CHMAP_FIXED &&
- type <= SND_CTL_TLVT_CHMAP_PAIRED);
-}
-
-enum { CHMAP_CTL_QUERY, CHMAP_CTL_GET, CHMAP_CTL_SET };
-
-static int chmap_caps(snd_pcm_hw_t *hw, int type)
-{
- if (hw->chmap_caps & (1 << type))
- return 1;
- if (hw->chmap_caps & (1 << (type + 8)))
- return 0;
- return 1;
+ snd_ctl_elem_id_set_device(id, dev);
+ snd_ctl_elem_id_set_index(id, subdev);
}
-static void chmap_caps_set_ok(snd_pcm_hw_t *hw, int type)
+static void fill_chmap_ctl_id(snd_pcm_t *pcm, snd_ctl_elem_id_t *id)
{
- hw->chmap_caps |= (1 << type);
+ snd_pcm_hw_t *hw = pcm->private_data;
+ return __fill_chmap_ctl_id(id, hw->device, hw->subdevice, pcm->stream);
}
-static void chmap_caps_set_error(snd_pcm_hw_t *hw, int type)
+static int is_chmap_type(int type)
{
- hw->chmap_caps |= (1 << (type + 8));
+ return (type >= SND_CTL_TLVT_CHMAP_FIXED &&
+ type <= SND_CTL_TLVT_CHMAP_PAIRED);
}
-static snd_pcm_chmap_query_t **snd_pcm_hw_query_chmaps(snd_pcm_t *pcm)
+/**
+ * \!brief Query the available channel maps
+ * \param card the card number
+ * \param dev the PCM device number
+ * \param subdev the PCM substream index
+ * \param stream the direction of PCM stream
+ * \return the NULL-terminated array of integer pointers, or NULL at error.
+ *
+ * This function works like snd_pcm_query_chmaps() but it takes the card,
+ * device, substream and stream numbers instead of the already opened
+ * snd_pcm_t instance, so that you can query available channel maps of
+ * a PCM before actually opening it.
+ *
+ * As the parameters stand, the query is performed only to the hw PCM
+ * devices, not the abstracted PCM object in alsa-lib.
+ */
+snd_pcm_chmap_query_t **
+snd_pcm_query_chmaps_from_hw(int card, int dev, int subdev,
+ snd_pcm_stream_t stream)
{
- snd_pcm_hw_t *hw = pcm->private_data;
snd_ctl_t *ctl;
snd_ctl_elem_id_t *id;
unsigned int tlv[256], *start;
snd_pcm_chmap_query_t **map;
int i, ret, nums;
- if (!chmap_caps(hw, CHMAP_CTL_QUERY))
- return NULL;
-
- ret = snd_ctl_hw_open(&ctl, NULL, hw->card, 0);
+ ret = snd_ctl_hw_open(&ctl, NULL, card, 0);
if (ret < 0) {
SYSMSG("Cannot open the associated CTL\n");
- goto error;
+ return NULL;
}
snd_ctl_elem_id_alloca(&id);
- fill_chmap_ctl_id(pcm, id);
+ __fill_chmap_ctl_id(id, dev, subdev, stream);
ret = snd_ctl_elem_tlv_read(ctl, id, tlv, sizeof(tlv));
snd_ctl_close(ctl);
if (ret < 0) {
SYSMSG("Cannot read Channel Map TLV\n");
- goto error;
+ return NULL;
}
#if 0
for (i = 0; i < 32; i++)
fprintf(stderr, "%02x: %08x\n", i, tlv[i]);
#endif
+ /* FIXME: the parser below assumes that the TLV only contains
+ * chmap-related blocks
+ */
if (tlv[0] != SND_CTL_TLVT_CONTAINER) {
if (!is_chmap_type(tlv[0])) {
SYSMSG("Invalid TLV type %d\n", tlv[0]);
- goto error;
+ return NULL;
}
start = tlv;
nums = 1;
@@ -1092,7 +1094,7 @@ static snd_pcm_chmap_query_t **snd_pcm_h
for (p = start; size > 0; ) {
if (!is_chmap_type(p[0])) {
SYSMSG("Invalid TLV type %d\n", p[0]);
- goto error;
+ return NULL;
}
nums++;
size -= p[1] + 8;
@@ -1113,12 +1115,45 @@ static snd_pcm_chmap_query_t **snd_pcm_h
memcpy(map[i]->map.pos, start + 2, start[1]);
start += start[1] / 4 + 2;
}
- chmap_caps_set_ok(hw, CHMAP_CTL_QUERY);
return map;
+}
+
+enum { CHMAP_CTL_QUERY, CHMAP_CTL_GET, CHMAP_CTL_SET };
+
+static int chmap_caps(snd_pcm_hw_t *hw, int type)
+{
+ if (hw->chmap_caps & (1 << type))
+ return 1;
+ if (hw->chmap_caps & (1 << (type + 8)))
+ return 0;
+ return 1;
+}
+
+static void chmap_caps_set_ok(snd_pcm_hw_t *hw, int type)
+{
+ hw->chmap_caps |= (1 << type);
+}
- error:
- chmap_caps_set_error(hw, CHMAP_CTL_QUERY);
- return NULL;
+static void chmap_caps_set_error(snd_pcm_hw_t *hw, int type)
+{
+ hw->chmap_caps |= (1 << (type + 8));
+}
+
+static snd_pcm_chmap_query_t **snd_pcm_hw_query_chmaps(snd_pcm_t *pcm)
+{
+ snd_pcm_hw_t *hw = pcm->private_data;
+ snd_pcm_chmap_query_t **map;
+
+ if (!chmap_caps(hw, CHMAP_CTL_QUERY))
+ return NULL;
+
+ map = snd_pcm_query_chmaps_from_hw(hw->card, hw->device,
+ hw->subdevice, pcm->stream);
+ if (map)
+ chmap_caps_set_ok(hw, CHMAP_CTL_QUERY);
+ else
+ chmap_caps_set_error(hw, CHMAP_CTL_QUERY);
+ return map;
}
static snd_pcm_chmap_t *snd_pcm_hw_get_chmap(snd_pcm_t *pcm)
