aplay: More support for channel map option

Now aplay tries to follow the given channel map by rearranging the
channels even when the channel map override isn't allowed but if the
device is still capable to return a channel map.

Also update the man page appropriately.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

2 files changed, 149 insertions, 11 deletions

diff --git a/aplay/aplay.1 b/aplay/aplay.1
index bf9b53e..18464ca 100644
--- a/aplay/aplay.1
+++ b/aplay/aplay.1
@@ -141,6 +141,17 @@ by typing arecord.
 Allow interactive operation via stdin.
 Currently only pause/resume via space or enter key is implemented.
 .TP
+\fI-m, \-\-chmap=ch1,ch2,...\fP
+Give the channel map to override or follow.  Pass channel position
+strings like \fIFL\fP, \fIFR\fP, etc.
+
+If a device supports the override of the channel map, \fBaplay\fP
+tries to pass the given channel map.
+If it doesn't support the channel map override but still it provides
+the channel map information, \fBaplay\fP tries to rearrange the
+channel order in the buffer to match with the returned channel map
+from the device.
+.TP
 \fI\-\-disable\-resample\fP
 Disable automatic rate resample.
 .TP
diff --git a/aplay/aplay.c b/aplay/aplay.c
index a4e5846..492a13b 100644
--- a/aplay/aplay.c
+++ b/aplay/aplay.c
@@ -145,7 +145,8 @@ FILE *pidf = NULL;
 static int pidfile_written = 0;
 
 #ifdef CONFIG_SUPPORT_CHMAP
-static snd_pcm_chmap_t *channel_map = NULL;
+static snd_pcm_chmap_t *channel_map = NULL; /* chmap to override */
+static unsigned int *hw_map = NULL; /* chmap to follow */
 #endif
 
 /* needed prototypes */
@@ -222,6 +223,7 @@ _("Usage: %s [OPTION]... [FILE]...\n"
 "-V, --vumeter=TYPE      enable VU meter (TYPE: mono or stereo)\n"
 "-I, --separate-channels one file for each channel\n"
 "-i, --interactive       allow interactive operation from stdin\n"
+"-m, --chmap=ch1,ch2,..  Give the channel map to override or follow\n"
 "    --disable-resample  disable automatic rate resample\n"
 "    --disable-channels  disable automatic channel conversions\n"
 "    --disable-format    disable automatic format conversions\n"
@@ -236,7 +238,6 @@ _("Usage: %s [OPTION]... [FILE]...\n"
 "    --use-strftime      apply the strftime facility to the output file name\n"
 "    --dump-hw-params    dump hw_params of the device\n"
 "    --fatal-errors      treat all errors as fatal\n"
-"-m, --chmap=ch1,ch2,..  Give the channel map to override\n"
   )
 		, command);
 	printf(_("Recognized sample formats are:"));
@@ -1083,6 +1084,74 @@ static void show_available_sample_formats(snd_pcm_hw_params_t* params)
 	}
 }
 
+#ifdef CONFIG_SUPPORT_CHMAP
+static int setup_chmap(void)
+{
+	snd_pcm_chmap_t *chmap = channel_map;
+	char mapped[hwparams.channels];
+	snd_pcm_chmap_t *hw_chmap;
+	unsigned int ch, i;
+	int err;
+
+	if (!chmap)
+		return 0;
+
+	if (chmap->channels != hwparams.channels) {
+		error(_("Channel numbers don't match between hw_params and channel map"));
+		return -1;
+	}
+	err = snd_pcm_set_chmap(handle, chmap);
+	if (!err)
+		return 0;
+
+	hw_chmap = snd_pcm_get_chmap(handle);
+	if (!hw_chmap) {
+		fprintf(stderr, _("Warning: unable to get channel map\n"));
+		return 0;
+	}
+
+	if (hw_chmap->channels == chmap->channels &&
+	    !memcmp(hw_chmap, chmap, 4 * (chmap->channels + 1))) {
+		/* maps are identical, so no need to convert */
+		free(hw_chmap);
+		return 0;
+	}
+
+	hw_map = calloc(hwparams.channels, sizeof(int));
+	if (!hw_map) {
+		error(_("not enough memory"));
+		return -1;
+	}
+
+	memset(mapped, 0, sizeof(mapped));
+	for (ch = 0; ch < hw_chmap->channels; ch++) {
+		if (chmap->pos[ch] == hw_chmap->pos[ch]) {
+			mapped[ch] = 1;
+			hw_map[ch] = ch;
+			continue;
+		}
+		for (i = 0; i < hw_chmap->channels; i++) {
+			if (!mapped[i] && chmap->pos[ch] == hw_chmap->pos[i]) {
+				mapped[i] = 1;
+				hw_map[ch] = i;
+				break;
+			}
+		}
+		if (i >= hw_chmap->channels) {
+			char buf[256];
+			error(_("Channel %d doesn't match with hw_parmas"), ch);
+			snd_pcm_chmap_print(hw_chmap, sizeof(buf), buf);
+			fprintf(stderr, "hardware chmap = %s\n", buf);
+			return -1;
+		}
+	}
+	free(hw_chmap);
+	return 0;
+}
+#else
+#define setup_chmap()	0
+#endif
+
 static void set_params(void)
 {
 	snd_pcm_hw_params_t *params;
@@ -1232,15 +1301,8 @@ static void set_params(void)
 		prg_exit(EXIT_FAILURE);
 	}
 
-#ifdef CONFIG_SUPPORT_CHMAP
-	if (channel_map) {
-		err = snd_pcm_set_chmap(handle, channel_map);
-		if (err < 0) {
-			error(_("Unable to set channel map"));
-			prg_exit(EXIT_FAILURE);
-		}
-	}
-#endif
+	if (setup_chmap())
+		prg_exit(EXIT_FAILURE);
 
 	if (verbose)
 		snd_pcm_dump(handle, log);
@@ -1743,6 +1805,69 @@ static void do_test_position(void)
 }
 
 /*
+ */
+#ifdef CONFIG_SUPPORT_CHMAP
+static u_char *remap_data(u_char *data, size_t count)
+{
+	static u_char *tmp, *src, *dst;
+	static size_t tmp_size;
+	size_t sample_bytes = bits_per_sample / 8;
+	size_t step = bits_per_frame / 8;
+	size_t chunk_bytes;
+	unsigned int ch, i;
+
+	if (!hw_map)
+		return data;
+
+	chunk_bytes = count * bits_per_frame / 8;
+	if (tmp_size < chunk_bytes) {
+		free(tmp);
+		tmp = malloc(chunk_bytes);
+		if (!tmp) {
+			error(_("not enough memory"));
+			exit(1);
+		}
+		tmp_size = count;
+	}
+
+	src = data;
+	dst = tmp;
+	for (i = 0; i < count; i++) {
+		for (ch = 0; ch < hwparams.channels; ch++) {
+			memcpy(dst, src + sample_bytes * hw_map[ch],
+			       sample_bytes);
+			dst += sample_bytes;
+		}
+		src += step;
+	}
+	return tmp;
+}
+
+static u_char **remap_datav(u_char **data, size_t count)
+{
+	static u_char **tmp;
+	unsigned int ch;
+
+	if (!hw_map)
+		return data;
+
+	if (!tmp) {
+		tmp = malloc(sizeof(*tmp) * hwparams.channels);
+		if (!tmp) {
+			error(_("not enough memory"));
+			exit(1);
+		}
+		for (ch = 0; ch < hwparams.channels; ch++)
+			tmp[ch] = data[hw_map[ch]];
+	}
+	return tmp;
+}
+#else
+#define remap_data(data, count)		(data)
+#define remapv_data(data, count)	(data)
+#endif
+
+/*
  *  write function
  */
 
@@ -1755,6 +1880,7 @@ static ssize_t pcm_write(u_char *data, size_t count)
 		snd_pcm_format_set_silence(hwparams.format, data + count * bits_per_frame / 8, (chunk_size - count) * hwparams.channels);
 		count = chunk_size;
 	}
+	data = remap_data(data, count);
 	while (count > 0) {
 		if (test_position)
 			do_test_position();
@@ -1797,6 +1923,7 @@ static ssize_t pcm_writev(u_char **data, unsigned int channels, size_t count)
 			snd_pcm_format_set_silence(hwparams.format, data[channel] + offset * bits_per_sample / 8, remaining);
 		count = chunk_size;
 	}
+	data = remap_datav(data, count);
 	while (count > 0) {
 		unsigned int channel;
 		void *bufs[channels];