The xawtv3 copy of alsa_stream.c has several improvements / bug fixes,
sync these into tvtime.
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
src/alsa_stream.c | 199 +++++++++++++++++++++++++++++++++++++-----------------
1 file changed, 136 insertions(+), 63 deletions(-)
diff --git a/src/alsa_stream.c b/src/alsa_stream.c
index 99cea05..509787a 100644
--- a/src/alsa_stream.c
+++ b/src/alsa_stream.c
@@ -1,8 +1,9 @@
/*
- * tvtime ALSA device support
+ * ALSA streaming support
*
- * Copyright (c) by Devin Heitmueller <dheitmueller@xxxxxxxxxxxxxx>
- *
+ * Originally written by:
+ * Copyright (c) by Devin Heitmueller <dheitmueller@xxxxxxxxxxxxxx>
+ * for usage at tvtime
* Derived from the alsa-driver test tool latency.c:
* Copyright (c) by Jaroslav Kysela <perex@xxxxxxxx>
*
@@ -25,6 +26,8 @@
*
*/
+#include "config.h"
+
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@@ -37,8 +40,9 @@
#include <math.h>
#include "alsa_stream.h"
+#define ARRAY_SIZE(a) (sizeof(a)/sizeof(*(a)))
+
/* Private vars to control alsa thread status */
-static int alsa_is_running = 0;
static int stop_alsa = 0;
/* Error handlers */
@@ -56,7 +60,7 @@ struct final_params {
static int setparams_stream(snd_pcm_t *handle,
snd_pcm_hw_params_t *params,
snd_pcm_format_t format,
- int channels,
+ int *channels,
const char *id)
{
int err;
@@ -83,10 +87,16 @@ static int setparams_stream(snd_pcm_t *handle,
snd_strerror(err));
return err;
}
- err = snd_pcm_hw_params_set_channels(handle, params, channels);
+
+retry:
+ err = snd_pcm_hw_params_set_channels(handle, params, *channels);
if (err < 0) {
+ if (strcmp(id, "capture") == 0 && *channels == 2) {
+ *channels = 1;
+ goto retry; /* Retry with mono capture */
+ }
fprintf(error_fp, "alsa: Channels count (%i) not available for %s: %s\n",
- channels, id, snd_strerror(err));
+ *channels, id, snd_strerror(err));
return err;
}
@@ -97,9 +107,10 @@ static void getparams_periods(snd_pcm_t *handle,
snd_pcm_hw_params_t *params,
unsigned int *usecs,
unsigned int *count,
- const char *id)
+ int allow_adjust, const char *id)
{
unsigned min = 0, max = 0;
+ unsigned desired = *usecs * *count;
snd_pcm_hw_params_get_periods_min(params, &min, 0);
snd_pcm_hw_params_get_periods_max(params, &max, 0);
@@ -125,6 +136,13 @@ static void getparams_periods(snd_pcm_t *handle,
if (*usecs > max)
*usecs = max;
}
+
+ /* If we deviate from the desired size by more then 20% adjust count */
+ if (allow_adjust && (((*usecs * *count) < (desired * 8 / 10)) ||
+ ((*usecs * *count) > (desired * 12 / 10)))) {
+ *count = (desired + *usecs / 2) / *usecs;
+ getparams_periods(handle, params, usecs, count, 0, id);
+ }
}
static int setparams_periods(snd_pcm_t *handle,
@@ -199,6 +217,33 @@ static int setparams_set(snd_pcm_t *handle,
return 0;
}
+static int alsa_try_rate(snd_pcm_t *phandle, snd_pcm_t *chandle,
+ snd_pcm_hw_params_t *p_hwparams,
+ snd_pcm_hw_params_t *c_hwparams,
+ int allow_resample, unsigned *ratep, unsigned *ratec)
+{
+ int err;
+
+ err = snd_pcm_hw_params_set_rate_near(chandle, c_hwparams, ratec, 0);
+ if (err)
+ return err;
+
+ *ratep = *ratec;
+ err = snd_pcm_hw_params_set_rate_near(phandle, p_hwparams, ratep, 0);
+ if (err)
+ return err;
+
+ if (*ratep == *ratec)
+ return 0;
+
+ if (verbose)
+ fprintf(error_fp,
+ "alsa_try_rate: capture wanted %u, playback wanted %u%s\n",
+ *ratec, *ratep, allow_resample ? " with resample enabled": "");
+
+ return 1; /* No error, but also no match */
+}
+
static int setparams(snd_pcm_t *phandle, snd_pcm_t *chandle,
snd_pcm_format_t format,
int latency, int allow_resample,
@@ -214,16 +259,17 @@ static int setparams(snd_pcm_t *phandle, snd_pcm_t *chandle,
/* Our latency is 2 periods (in usecs) */
unsigned int c_periods = 2, p_periods;
unsigned int c_periodtime, p_periodtime;
+ const unsigned int prefered_rates[] = { 44100, 48000, 32000 };
snd_pcm_hw_params_alloca(&p_hwparams);
snd_pcm_hw_params_alloca(&c_hwparams);
snd_pcm_sw_params_alloca(&p_swparams);
snd_pcm_sw_params_alloca(&c_swparams);
- if (setparams_stream(phandle, p_hwparams, format, channels, "playback"))
+ if (setparams_stream(chandle, c_hwparams, format, &channels, "capture"))
return 1;
- if (setparams_stream(chandle, c_hwparams, format, channels, "capture"))
+ if (setparams_stream(phandle, p_hwparams, format, &channels, "playback"))
return 1;
if (allow_resample) {
@@ -258,25 +304,40 @@ static int setparams(snd_pcm_t *phandle, snd_pcm_t *chandle,
}
if (verbose)
- fprintf(error_fp, "alsa: Will search a common rate between %u and %u\n",
+ fprintf(error_fp,
+ "alsa: Will search a common rate between %u and %u\n",
ratemin, ratemax);
- for (i = ratemax; i <= ratemin; i -= 100) {
- err = snd_pcm_hw_params_set_rate_near(chandle, c_hwparams, &i, 0);
- if (err)
- continue;
- ratec = i;
- ratep = i;
- err = snd_pcm_hw_params_set_rate_near(phandle, p_hwparams, &ratep, 0);
- if (err)
- continue;
- if (ratep == ratec)
- break;
- if (verbose)
- fprintf(error_fp,
- "alsa: Failed to set to %u: capture wanted %u, playback wanted %u%s\n",
- i, ratec, ratep,
- allow_resample ? " with resample enabled": "");
+ /* First try a set of common rates */
+ err = -1;
+ for (i = 0; i < ARRAY_SIZE(prefered_rates); i++) {
+ if (prefered_rates[i] < ratemin || prefered_rates[i] > ratemax)
+ continue;
+ ratep = ratec = prefered_rates[i];
+ err = alsa_try_rate(phandle, chandle, p_hwparams, c_hwparams,
+ allow_resample, &ratep, &ratec);
+ if (err == 0)
+ break;
+ }
+
+ if (err != 0) {
+ if (ratemin >= 44100) {
+ for (i = ratemin; i <= ratemax; i += 100) {
+ ratep = ratec = i;
+ err = alsa_try_rate(phandle, chandle, p_hwparams, c_hwparams,
+ allow_resample, &ratep, &ratec);
+ if (err == 0)
+ break;
+ }
+ } else {
+ for (i = ratemax; i >= ratemin; i -= 100) {
+ ratep = ratec = i;
+ err = alsa_try_rate(phandle, chandle, p_hwparams, c_hwparams,
+ allow_resample, &ratep, &ratec);
+ if (err == 0)
+ break;
+ }
+ }
}
if (err < 0) {
@@ -293,15 +354,19 @@ static int setparams(snd_pcm_t *phandle, snd_pcm_t *chandle,
if (verbose)
fprintf(error_fp, "alsa: Using Rate %d\n", ratec);
- /* Negociate period parameters */
+ /* Negotiate period parameters */
c_periodtime = latency * 1000 / c_periods;
- getparams_periods(chandle, c_hwparams, &c_periodtime, &c_periods, "capture");
+ getparams_periods(chandle, c_hwparams, &c_periodtime, &c_periods, 1, "capture");
p_periods = c_periods * 2;
p_periodtime = c_periodtime;
- getparams_periods(phandle, p_hwparams, &p_periodtime, &p_periods, "playback");
+ getparams_periods(phandle, p_hwparams, &p_periodtime, &p_periods, 0, "playback");
c_periods = p_periods / 2;
+ if (verbose)
+ fprintf(error_fp, "alsa: Capture %u periods of %u usecs, Playback %u periods of %u usecs\n",
+ c_periods, c_periodtime, p_periods, p_periodtime);
+
/*
* Some playback devices support a very limited periodtime range. If the user needs to
* use a higher latency to avoid overrun/underrun, use an alternate algorithm of incresing
@@ -310,10 +375,10 @@ static int setparams(snd_pcm_t *phandle, snd_pcm_t *chandle,
if (p_periodtime < c_periodtime) {
c_periodtime = p_periodtime;
c_periods = round (latency * 1000.0 / c_periodtime + 0.5);
- getparams_periods(chandle, c_hwparams, &c_periodtime, &c_periods, "capture");
+ getparams_periods(chandle, c_hwparams, &c_periodtime, &c_periods, 0, "capture");
p_periods = c_periods * 2;
p_periodtime = c_periodtime;
- getparams_periods(phandle, p_hwparams, &p_periodtime, &p_periods, "playback");
+ getparams_periods(phandle, p_hwparams, &p_periodtime, &p_periods, 0, "playback");
c_periods = p_periods / 2;
}
@@ -427,6 +492,7 @@ static int alsa_stream(const char *pdevice, const char *cdevice, int latency)
SND_PCM_NONBLOCK)) < 0) {
fprintf(error_fp, "alsa: Cannot open capture device %s: %s\n",
cdevice, snd_strerror(err));
+ snd_pcm_close(phandle);
return 0;
}
@@ -445,6 +511,8 @@ static int alsa_stream(const char *pdevice, const char *cdevice, int latency)
0)) < 0) {
fprintf(error_fp, "alsa: Cannot open playback device %s: %s\n",
pdevice, snd_strerror(err));
+ snd_pcm_close(chandle);
+ return 0;
}
err = setparams(phandle, chandle, format, latency, 1, &negotiated);
@@ -452,6 +520,8 @@ static int alsa_stream(const char *pdevice, const char *cdevice, int latency)
if (err != 0) {
fprintf(error_fp, "alsa: setparams failed\n");
+ snd_pcm_close(phandle);
+ snd_pcm_close(chandle);
return 1;
}
@@ -459,20 +529,17 @@ static int alsa_stream(const char *pdevice, const char *cdevice, int latency)
* negotiated.channels);
if (buffer == NULL) {
fprintf(error_fp, "alsa: Failed allocating buffer for audio\n");
+ snd_pcm_close(phandle);
+ snd_pcm_close(chandle);
return 0;
}
- /*
- * Buffering delay is due for capture and for playback, so we
- * need to multiply it by two.
- */
- fprintf(error_fp,
+ if (verbose)
+ fprintf(error_fp,
"alsa: stream started from %s to %s (%i Hz, buffer delay = %.2f ms)\n",
cdevice, pdevice, negotiated.rate,
negotiated.latency * 1000.0 / negotiated.rate);
- alsa_is_running = 1;
-
while (!stop_alsa) {
/* We start with a read and not a wait to auto(re)start the capture */
r = readbuf(chandle, buffer, negotiated.bufsize);
@@ -481,12 +548,12 @@ static int alsa_stream(const char *pdevice, const char *cdevice, int latency)
if (r > 0)
writebuf(phandle, buffer, r);
/* use poll to wait for next event */
- snd_pcm_wait(chandle, 1000);
+ while (!stop_alsa && !snd_pcm_wait(chandle, 50))
+ ;
}
snd_pcm_drop(chandle);
- snd_pcm_nonblock(phandle, 0);
- snd_pcm_drain(phandle);
+ snd_pcm_drop(phandle);
snd_pcm_unlink(chandle);
snd_pcm_hw_free(phandle);
@@ -495,7 +562,6 @@ static int alsa_stream(const char *pdevice, const char *cdevice, int latency)
snd_pcm_close(phandle);
snd_pcm_close(chandle);
- alsa_is_running = 0;
return 0;
}
@@ -513,7 +579,8 @@ static void *alsa_thread_entry(void *whatever)
fprintf(error_fp, "alsa: starting copying alsa stream from %s to %s\n",
inputs->cdevice, inputs->pdevice);
alsa_stream(inputs->pdevice, inputs->cdevice, inputs->latency);
- fprintf(error_fp, "alsa: stream stopped\n");
+ if (verbose)
+ fprintf(error_fp, "alsa: stream stopped\n");
free(inputs->pdevice);
free(inputs->cdevice);
@@ -526,12 +593,18 @@ static void *alsa_thread_entry(void *whatever)
Public functions
*************************************************************************/
+static int alsa_is_running = 0;
+static pthread_t alsa_thread;
+
int alsa_thread_startup(const char *pdevice, const char *cdevice, int latency,
FILE *__error_fp, int __verbose)
{
int ret;
- pthread_t thread;
- struct input_params *inputs = malloc(sizeof(struct input_params));
+ struct input_params *inputs;
+
+ if ((strcasecmp(pdevice, "disabled") == 0) ||
+ (strcasecmp(cdevice, "disabled") == 0))
+ return 0;
if (__error_fp)
error_fp = __error_fp;
@@ -540,41 +613,41 @@ int alsa_thread_startup(const char *pdevice, const char *cdevice, int latency,
verbose = __verbose;
+ if (alsa_is_running) {
+ fprintf(error_fp, "alsa: Already running\n");
+ return EBUSY;
+ }
+ inputs = malloc(sizeof(struct input_params));
if (inputs == NULL) {
fprintf(error_fp, "alsa: failed allocating memory for inputs\n");
- return 0;
- }
-
- if ((strcasecmp(pdevice, "disabled") == 0) ||
- (strcasecmp(cdevice, "disabled") == 0)) {
- free(inputs);
- return 0;
+ return ENOMEM;
}
inputs->pdevice = strdup(pdevice);
inputs->cdevice = strdup(cdevice);
inputs->latency = latency;
- if (alsa_is_running) {
- stop_alsa = 1;
- while ((volatile int)alsa_is_running)
- usleep(10);
- }
-
stop_alsa = 0;
-
- ret = pthread_create(&thread, NULL,
+ ret = pthread_create(&alsa_thread, NULL,
&alsa_thread_entry, (void *) inputs);
+ if (ret == 0)
+ alsa_is_running = 1;
+
return ret;
}
void alsa_thread_stop(void)
{
- stop_alsa = 1;
+ if (!alsa_is_running)
+ return;
+
+ stop_alsa = 1;
+ pthread_join(alsa_thread, NULL);
+ alsa_is_running = 0;
}
int alsa_thread_is_running(void)
{
- return alsa_is_running;
+ return alsa_is_running;
}
--
2.5.0
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
