There are several issues with the original alsa_stream code that got
fixed on xawtv3, made by me and by Hans de Goede. Basically, the
code were re-written, in order to follow the alsa best practises.
Backport the changes from xawtv, in order to make it to work on a
wider range of V4L and sound adapters.
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
---
src/alsa_stream.c | 629 ++++++++++++++++++++++++++++++-----------------------
src/alsa_stream.h | 6 +-
src/tvtime.c | 6 +-
3 files changed, 363 insertions(+), 278 deletions(-)
diff --git a/src/alsa_stream.c b/src/alsa_stream.c
index 2243b02..b6a41a5 100644
--- a/src/alsa_stream.c
+++ b/src/alsa_stream.c
@@ -6,6 +6,9 @@
* Derived from the alsa-driver test tool latency.c:
* Copyright (c) by Jaroslav Kysela <perex@xxxxxxxx>
*
+ * Copyright (c) 2011 - Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
+ * Ported to xawtv, with bug fixes and improvements
+ *
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
@@ -32,8 +35,16 @@
#include <alsa/asoundlib.h>
#include <sys/time.h>
#include <math.h>
+#include "alsa_stream.h"
+
+/* Private vars to control alsa thread status */
+static int alsa_is_running = 0;
+static int stop_alsa = 0;
+/* Error handlers */
snd_output_t *output = NULL;
+FILE *error_fp;
+int verbose = 0;
struct final_params {
int bufsize;
@@ -42,403 +53,435 @@ struct final_params {
int channels;
};
-int setparams_stream(snd_pcm_t *handle,
- snd_pcm_hw_params_t *params,
- snd_pcm_format_t format,
- int channels,
- int rate,
- const char *id)
+static int setparams_stream(snd_pcm_t *handle,
+ snd_pcm_hw_params_t *params,
+ snd_pcm_format_t format,
+ int channels,
+ const char *id)
{
int err;
- unsigned int rrate;
err = snd_pcm_hw_params_any(handle, params);
if (err < 0) {
- printf("Broken configuration for %s PCM: no configurations available: %s\n", snd_strerror(err), id);
- return err;
- }
- err = snd_pcm_hw_params_set_rate_resample(handle, params, 1);
- if (err < 0) {
- printf("Resample setup failed for %s: %s\n", id, snd_strerror(err));
+ fprintf(error_fp,
+ "alsa: Broken configuration for %s PCM: no configurations available: %s\n",
+ snd_strerror(err), id);
return err;
}
+
err = snd_pcm_hw_params_set_access(handle, params,
SND_PCM_ACCESS_RW_INTERLEAVED);
if (err < 0) {
- printf("Access type not available for %s: %s\n", id,
- snd_strerror(err));
+ fprintf(error_fp, "alsa: Access type not available for %s: %s\n", id,
+ snd_strerror(err));
return err;
}
err = snd_pcm_hw_params_set_format(handle, params, format);
if (err < 0) {
- printf("Sample format not available for %s: %s\n", id,
+ fprintf(error_fp, "alsa: Sample format not available for %s: %s\n", id,
snd_strerror(err));
return err;
}
err = snd_pcm_hw_params_set_channels(handle, params, channels);
if (err < 0) {
- printf("Channels count (%i) not available for %s: %s\n", channels, id,
- snd_strerror(err));
- return err;
- }
- rrate = rate;
- err = snd_pcm_hw_params_set_rate_near(handle, params, &rrate, 0);
- if (err < 0) {
- printf("Rate %iHz not available for %s: %s\n", rate, id,
- snd_strerror(err));
+ fprintf(error_fp, "alsa: Channels count (%i) not available for %s: %s\n",
+ channels, id, snd_strerror(err));
return err;
}
- if ((int)rrate != rate) {
- printf("Rate doesn't match (requested %iHz, get %iHz)\n", rate, err);
- return -EINVAL;
- }
+
return 0;
}
-int setparams_bufsize(snd_pcm_t *handle,
+static void getparams_periods(snd_pcm_t *handle,
snd_pcm_hw_params_t *params,
- snd_pcm_hw_params_t *tparams,
- snd_pcm_uframes_t bufsize,
- int period_size,
+ unsigned int *usecs,
+ unsigned int *count,
+ const char *id)
+{
+ unsigned min = 0, max = 0;
+
+ snd_pcm_hw_params_get_periods_min(params, &min, 0);
+ snd_pcm_hw_params_get_periods_max(params, &max, 0);
+ if (min && max) {
+ if (verbose)
+ fprintf(error_fp, "alsa: %s periods range between %u and %u. Want: %u\n",
+ id, min, max, *count);
+ if (*count < min)
+ *count = min;
+ if (*count > max)
+ *count = max;
+ }
+
+ min = max = 0;
+ snd_pcm_hw_params_get_period_time_min(params, &min, 0);
+ snd_pcm_hw_params_get_period_time_max(params, &max, 0);
+ if (min && max) {
+ if (verbose)
+ fprintf(error_fp, "alsa: %s period time range between %u and %u. Want: %u\n",
+ id, min, max, *usecs);
+ if (*usecs < min)
+ *usecs = min;
+ if (*usecs > max)
+ *usecs = max;
+ }
+}
+
+static int setparams_periods(snd_pcm_t *handle,
+ snd_pcm_hw_params_t *params,
+ unsigned int *usecs,
+ unsigned int *count,
const char *id)
{
int err;
- snd_pcm_uframes_t periodsize;
- snd_pcm_hw_params_copy(params, tparams);
- periodsize = bufsize * 2;
- err = snd_pcm_hw_params_set_buffer_size_near(handle, params, &periodsize);
+ err = snd_pcm_hw_params_set_period_time_near(handle, params, usecs, 0);
if (err < 0) {
- printf("Unable to set buffer size %li for %s: %s\n",
- bufsize * 2, id, snd_strerror(err));
- return err;
+ fprintf(error_fp, "alsa: Unable to set period time %u for %s: %s\n",
+ *usecs, id, snd_strerror(err));
+ return err;
}
- if (period_size > 0)
- periodsize = period_size;
- else
- periodsize /= 2;
- err = snd_pcm_hw_params_set_period_size_near(handle, params, &periodsize,
- 0);
+
+ err = snd_pcm_hw_params_set_periods_near(handle, params, count, 0);
if (err < 0) {
- printf("Unable to set period size %li for %s: %s\n", periodsize, id,
- snd_strerror(err));
+ fprintf(error_fp, "alsa: Unable to set %u periods for %s: %s\n",
+ *count, id, snd_strerror(err));
return err;
}
+
+ if (verbose)
+ fprintf(error_fp, "alsa: %s period set to %u periods of %u time\n",
+ id, *count, *usecs);
+
return 0;
}
-int setparams_set(snd_pcm_t *handle,
- snd_pcm_hw_params_t *params,
- snd_pcm_sw_params_t *swparams,
- const char *id)
+static int setparams_set(snd_pcm_t *handle,
+ snd_pcm_hw_params_t *params,
+ snd_pcm_sw_params_t *swparams,
+ snd_pcm_uframes_t start_treshold,
+ const char *id)
{
int err;
err = snd_pcm_hw_params(handle, params);
if (err < 0) {
- printf("Unable to set hw params for %s: %s\n", id, snd_strerror(err));
+ fprintf(error_fp, "alsa: Unable to set hw params for %s: %s\n",
+ id, snd_strerror(err));
return err;
}
err = snd_pcm_sw_params_current(handle, swparams);
if (err < 0) {
- printf("Unable to determine current swparams for %s: %s\n", id,
- snd_strerror(err));
+ fprintf(error_fp, "alsa: Unable to determine current swparams for %s: %s\n",
+ id, snd_strerror(err));
return err;
}
- err = snd_pcm_sw_params_set_start_threshold(handle, swparams, 0x7fffffff);
+ err = snd_pcm_sw_params_set_start_threshold(handle, swparams,
+ start_treshold);
if (err < 0) {
- printf("Unable to set start threshold mode for %s: %s\n", id,
- snd_strerror(err));
+ fprintf(error_fp, "alsa: Unable to set start threshold mode for %s: %s\n",
+ id, snd_strerror(err));
return err;
}
err = snd_pcm_sw_params_set_avail_min(handle, swparams, 4);
if (err < 0) {
- printf("Unable to set avail min for %s: %s\n", id, snd_strerror(err));
+ fprintf(error_fp, "alsa: Unable to set avail min for %s: %s\n",
+ id, snd_strerror(err));
return err;
}
err = snd_pcm_sw_params(handle, swparams);
if (err < 0) {
- printf("Unable to set sw params for %s: %s\n", id, snd_strerror(err));
+ fprintf(error_fp, "alsa: Unable to set sw params for %s: %s\n",
+ id, snd_strerror(err));
return err;
}
return 0;
}
-int setparams(snd_pcm_t *phandle, snd_pcm_t *chandle, snd_pcm_format_t format,
- struct final_params *negotiated)
+static int setparams(snd_pcm_t *phandle, snd_pcm_t *chandle,
+ snd_pcm_format_t format,
+ int latency, int allow_resample,
+ struct final_params *negotiated)
{
- int rate = 48000;
- int latency_min = 600; /* in frames / 2 */
- int channels = 2;
- int latency = latency_min - 4;
- int bufsize = latency;
- int err, last_bufsize = bufsize;
- snd_pcm_hw_params_t *pt_params, *ct_params;
- snd_pcm_hw_params_t *p_params, *c_params;
+ int i;
+ unsigned ratep, ratec = 0;
+ unsigned ratemin = 32000, ratemax = 96000, val;
+ int err, channels = 2;
+ snd_pcm_hw_params_t *p_hwparams, *c_hwparams;
snd_pcm_sw_params_t *p_swparams, *c_swparams;
- snd_pcm_uframes_t p_size, c_size, p_psize, c_psize;
- unsigned int p_time, c_time;
-
- snd_pcm_hw_params_alloca(&p_params);
- snd_pcm_hw_params_alloca(&c_params);
- snd_pcm_hw_params_alloca(&pt_params);
- snd_pcm_hw_params_alloca(&ct_params);
+ snd_pcm_uframes_t c_size, p_psize, c_psize;
+ /* Our latency is 2 periods (in usecs) */
+ unsigned int c_periods = 2, p_periods;
+ unsigned int c_periodtime, p_periodtime;
+
+ 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 ((err = setparams_stream(phandle, pt_params, format, channels, rate,
- "playback")) < 0) {
- printf("Unable to set parameters for playback stream: %s\n", snd_strerror(err));
- return 1;
- }
- if ((err = setparams_stream(chandle, ct_params, format, channels, rate,
- "capture")) < 0) {
- printf("Unable to set parameters for playback stream: %s\n", snd_strerror(err));
+
+ if (setparams_stream(phandle, p_hwparams, format, channels, "playback"))
return 1;
- }
- __again:
- if (last_bufsize == bufsize)
- bufsize += 4;
- last_bufsize = bufsize;
+ if (setparams_stream(chandle, c_hwparams, format, channels, "capture"))
+ return 1;
- if ((err = setparams_bufsize(phandle, p_params, pt_params, bufsize, 0,
- "playback")) < 0) {
- printf("Unable to set sw parameters for playback stream: %s\n",
- snd_strerror(err));
- return -1;
- }
- if ((err = setparams_bufsize(chandle, c_params, ct_params, bufsize, 0,
- "capture")) < 0) {
- printf("Unable to set sw parameters for playback stream: %s\n",
- snd_strerror(err));
- return -1;
+ if (allow_resample) {
+ err = snd_pcm_hw_params_set_rate_resample(chandle, c_hwparams, 1);
+ if (err < 0) {
+ fprintf(error_fp, "alsa: Resample setup failed: %s\n", snd_strerror(err));
+ return 1;
+ } else if (verbose)
+ fprintf(error_fp, "alsa: Resample enabled.\n");
+ }
+
+ err = snd_pcm_hw_params_get_rate_min(c_hwparams, &ratemin, 0);
+ if (err >= 0 && verbose)
+ fprintf(error_fp, "alsa: Capture min rate is %d\n", ratemin);
+ err = snd_pcm_hw_params_get_rate_max(c_hwparams, &ratemax, 0);
+ if (err >= 0 && verbose)
+ fprintf(error_fp, "alsa: Capture max rate is %u\n", ratemax);
+
+ err = snd_pcm_hw_params_get_rate_min(p_hwparams, &val, 0);
+ if (err >= 0) {
+ if (verbose)
+ fprintf(error_fp, "alsa: Playback min rate is %u\n", val);
+ if (val > ratemin)
+ ratemin = val;
+ }
+ err = snd_pcm_hw_params_get_rate_max(p_hwparams, &val, 0);
+ if (err >= 0) {
+ if (verbose)
+ fprintf(error_fp, "alsa: Playback max rate is %u\n", val);
+ if (val < ratemax)
+ ratemax = val;
+ }
+
+ if (verbose)
+ fprintf(error_fp, "alsa: Will search a common rate between %u and %u\n",
+ ratemin, ratemax);
+
+ for (i = ratemin; i <= ratemax; 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": "");
}
- snd_pcm_hw_params_get_period_size(p_params, &p_psize, NULL);
- if (p_psize > (unsigned int)bufsize)
- bufsize = p_psize;
-
- snd_pcm_hw_params_get_period_size(c_params, &c_psize, NULL);
- if (c_psize > (unsigned int)bufsize)
- bufsize = c_psize;
+ if (err < 0) {
+ fprintf(error_fp, "alsa: Failed to set a supported rate: %s\n",
+ snd_strerror(err));
+ return 1;
+ }
+ if (ratep != ratec) {
+ if (verbose || allow_resample)
+ fprintf(error_fp,
+ "alsa: Couldn't find a rate that it is supported by both playback and capture\n");
+ return 2;
+ }
+ if (verbose)
+ fprintf(error_fp, "alsa: Using Rate %d\n", ratec);
+
+ /* Negociate period parameters */
+
+ c_periodtime = latency * 1000 / c_periods;
+ getparams_periods(chandle, c_hwparams, &c_periodtime, &c_periods, "capture");
+ p_periods = c_periods * 2;
+ p_periodtime = c_periodtime;
+ getparams_periods(phandle, p_hwparams, &p_periodtime, &p_periods, "playback");
+ c_periods = p_periods / 2;
+
+ /*
+ * 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
+ * the number of periods, to archive the needed latency
+ */
+ 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");
+ p_periods = c_periods * 2;
+ p_periodtime = c_periodtime;
+ getparams_periods(phandle, p_hwparams, &p_periodtime, &p_periods, "playback");
+ c_periods = p_periods / 2;
+ }
+
+ if (setparams_periods(chandle, c_hwparams, &c_periodtime, &c_periods, "capture"))
+ return 1;
- snd_pcm_hw_params_get_period_time(p_params, &p_time, NULL);
- snd_pcm_hw_params_get_period_time(c_params, &c_time, NULL);
+ /* Note we use twice as much periods for the playback buffer, since we
+ will get a period size near the requested time and we don't want it to
+ end up smaller then the capture buffer as then we could end up blocking
+ on writing to it. Note we will configure the playback dev to start
+ playing as soon as it has 2 capture periods worth of data, so this
+ won't influence latency */
+ if (setparams_periods(phandle, p_hwparams, &p_periodtime, &p_periods, "playback"))
+ return 1;
- if (p_time != c_time)
- goto __again;
+ snd_pcm_hw_params_get_period_size(p_hwparams, &p_psize, NULL);
+ snd_pcm_hw_params_get_period_size(c_hwparams, &c_psize, NULL);
+ snd_pcm_hw_params_get_buffer_size(c_hwparams, &c_size);
- snd_pcm_hw_params_get_buffer_size(p_params, &p_size);
- if (p_psize * 2 < p_size)
- goto __again;
- snd_pcm_hw_params_get_buffer_size(c_params, &c_size);
- if (c_psize * 2 < c_size)
- goto __again;
+ latency = c_periods * c_psize;
+ if (setparams_set(phandle, p_hwparams, p_swparams, latency, "playback"))
+ return 1;
- if ((err = setparams_set(phandle, p_params, p_swparams, "playback")) < 0) {
- printf("Unable to set sw parameters for playback stream: %s\n",
- snd_strerror(err));
- return -1;
- }
- if ((err = setparams_set(chandle, c_params, c_swparams, "capture")) < 0) {
- printf("Unable to set sw parameters for playback stream: %s\n",
- snd_strerror(err));
- return -1;
- }
+ if (setparams_set(chandle, c_hwparams, c_swparams, c_psize, "capture"))
+ return 1;
if ((err = snd_pcm_prepare(phandle)) < 0) {
- printf("Prepare error: %s\n", snd_strerror(err));
- return -1;
+ fprintf(error_fp, "alsa: Prepare error: %s\n", snd_strerror(err));
+ return 1;
}
-#ifdef SHOW_ALSA_DEBUG
- printf("final config\n");
- snd_pcm_dump_setup(phandle, output);
- snd_pcm_dump_setup(chandle, output);
- printf("Parameters are %iHz, %s, %i channels\n", rate,
- snd_pcm_format_name(format), channels);
- fflush(stdout);
-#endif
+ if (verbose) {
+ fprintf(error_fp, "alsa: Negociated configuration:\n");
+ snd_pcm_dump_setup(phandle, output);
+ snd_pcm_dump_setup(chandle, output);
+ fprintf(error_fp, "alsa: Parameters are %iHz, %s, %i channels\n",
+ ratep, snd_pcm_format_name(format), channels);
+ fprintf(error_fp, "alsa: Set bitrate to %u%s, buffer size is %u\n", ratec,
+ allow_resample ? " with resample enabled at playback": "",
+ (unsigned int)c_size);
+ }
- negotiated->bufsize = bufsize;
- negotiated->rate = rate;
+ negotiated->bufsize = c_size;
+ negotiated->rate = ratep;
negotiated->channels = channels;
- negotiated->latency = bufsize;
+ negotiated->latency = latency;
return 0;
}
-void setscheduler(void)
-{
- struct sched_param sched_param;
-
- if (sched_getparam(0, &sched_param) < 0) {
- printf("Scheduler getparam failed...\n");
- return;
- }
- sched_param.sched_priority = sched_get_priority_max(SCHED_RR);
- if (!sched_setscheduler(0, SCHED_RR, &sched_param)) {
- printf("Scheduler set to Round Robin with priority %i...\n", sched_param.sched_priority);
- fflush(stdout);
- return;
- }
- printf("!!!Scheduler set to Round Robin with priority %i FAILED!!!\n", sched_param.sched_priority);
-}
-
-snd_pcm_sframes_t readbuf(snd_pcm_t *handle, char *buf, long len,
- size_t *frames, size_t *max)
+/* Read up to len frames */
+static snd_pcm_sframes_t readbuf(snd_pcm_t *handle, char *buf, long len)
{
snd_pcm_sframes_t r;
r = snd_pcm_readi(handle, buf, len);
- if (r < 0) {
- return r;
+ if (r < 0 && r != -EAGAIN) {
+ r = snd_pcm_recover(handle, r, 0);
+ if (r < 0)
+ fprintf(error_fp, "alsa: overrun recover error: %s\n", snd_strerror(r));
}
-
- if (r > 0) {
- *frames += r;
- if ((long)*max < r)
- *max = r;
- }
-
return r;
}
-snd_pcm_sframes_t writebuf(snd_pcm_t *handle, char *buf, long len,
- size_t *frames)
+/* Write len frames (note not up to len, but all of len!) */
+static snd_pcm_sframes_t writebuf(snd_pcm_t *handle, char *buf, long len)
{
snd_pcm_sframes_t r;
- while (len > 0) {
+ while (1) {
r = snd_pcm_writei(handle, buf, len);
+ if (r == len)
+ return 0;
if (r < 0) {
- return r;
+ r = snd_pcm_recover(handle, r, 0);
+ if (r < 0) {
+ fprintf(error_fp, "alsa: underrun recover error: %s\n",
+ snd_strerror(r));
+ return r;
+ }
}
-
buf += r * 4;
len -= r;
- *frames += r;
- }
- return 0;
-}
-
-int startup_capture(snd_pcm_t *phandle, snd_pcm_t *chandle,
- snd_pcm_format_t format, char *buffer, int latency,
- int channels)
-{
- size_t frames_out;
- int err;
-
- frames_out = 0;
- if (snd_pcm_format_set_silence(format, buffer, latency*channels) < 0) {
- fprintf(stderr, "silence error\n");
- return 1;
- }
- if (writebuf(phandle, buffer, latency, &frames_out) < 0) {
- fprintf(stderr, "write error\n");
- return 1;
+ snd_pcm_wait(handle, 100);
}
- if (writebuf(phandle, buffer, latency, &frames_out) < 0) {
- fprintf(stderr, "write error\n");
- return 1;
- }
-
- if ((err = snd_pcm_start(chandle)) < 0) {
- printf("Go error: %s\n", snd_strerror(err));
- return 1;
- }
- return 0;
}
-int tvtime_alsa_stream(const char *pdevice, const char *cdevice)
+static int alsa_stream(const char *pdevice, const char *cdevice, int latency)
{
snd_pcm_t *phandle, *chandle;
char *buffer;
int err;
ssize_t r;
- size_t frames_in, frames_out, in_max;
struct final_params negotiated;
- int ret = 0;
snd_pcm_format_t format = SND_PCM_FORMAT_S16_LE;
+ char pdevice_new[32];
- err = snd_output_stdio_attach(&output, stdout, 0);
+ err = snd_output_stdio_attach(&output, error_fp, 0);
if (err < 0) {
- printf("Output failed: %s\n", snd_strerror(err));
+ fprintf(error_fp, "alsa: Output failed: %s\n", snd_strerror(err));
return 0;
}
-// setscheduler();
-
- printf("Playback device is %s\n", pdevice);
- printf("Capture device is %s\n", cdevice);
-
/* Open the devices */
if ((err = snd_pcm_open(&phandle, pdevice, SND_PCM_STREAM_PLAYBACK,
- SND_PCM_NONBLOCK)) < 0) {
- printf("Cannot open ALSA Playback device %s: %s\n", pdevice,
- snd_strerror(err));
+ 0)) < 0) {
+ fprintf(error_fp, "alsa: Cannot open playback device %s: %s\n",
+ pdevice, snd_strerror(err));
return 0;
}
if ((err = snd_pcm_open(&chandle, cdevice, SND_PCM_STREAM_CAPTURE,
SND_PCM_NONBLOCK)) < 0) {
- printf("Cannot open ALSA Capture device %s: %s\n",
- cdevice, snd_strerror(err));
+ fprintf(error_fp, "alsa: Cannot open capture device %s: %s\n",
+ cdevice, snd_strerror(err));
return 0;
}
- frames_in = frames_out = 0;
- if (setparams(phandle, chandle, format, &negotiated) < 0) {
- printf("setparams failed\n");
+ err = setparams(phandle, chandle, format, latency, 0, &negotiated);
+
+ /* Try to use plughw instead, as it allows emulating speed */
+ if (err == 2 && strncmp(pdevice, "hw", 2) == 0) {
+
+ snd_pcm_close(phandle);
+
+ sprintf(pdevice_new, "plug%s", pdevice);
+ pdevice = pdevice_new;
+ if (verbose)
+ fprintf(error_fp, "alsa: Trying %s for playback\n", pdevice);
+ if ((err = snd_pcm_open(&phandle, pdevice, SND_PCM_STREAM_PLAYBACK,
+ 0)) < 0) {
+ fprintf(error_fp, "alsa: Cannot open playback device %s: %s\n",
+ pdevice, snd_strerror(err));
+ }
+
+ err = setparams(phandle, chandle, format, latency, 1, &negotiated);
+ }
+
+ if (err != 0) {
+ fprintf(error_fp, "alsa: setparams failed\n");
return 1;
}
buffer = malloc((negotiated.bufsize * snd_pcm_format_width(format) / 8)
* negotiated.channels);
if (buffer == NULL) {
- printf("Failed allocating buffer for audio\n");
+ fprintf(error_fp, "alsa: Failed allocating buffer for audio\n");
return 0;
-
- }
- if ((err = snd_pcm_link(chandle, phandle)) < 0) {
- printf("Streams link error: %d %s\n", err, snd_strerror(err));
- return 1;
}
- startup_capture(phandle, chandle, format, buffer, negotiated.latency,
- negotiated.channels);
-
- while (1) {
- in_max = 0;
-
+ /*
+ * Buffering delay is due for capture and for playback, so we
+ * need to multiply it by two.
+ */
+ 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);
+ if (r == 0) /* Succesfully recovered from an overrun? */
+ continue; /* Force restart of capture stream */
+ if (r > 0)
+ writebuf(phandle, buffer, r);
/* use poll to wait for next event */
- ret = snd_pcm_wait(chandle, 1000);
- if (ret < 0) {
- if ((err = snd_pcm_recover(chandle, ret, 0)) < 0) {
- fprintf(stderr, "xrun: recover error: %s",
- snd_strerror(err));
- break;
- }
-
- /* Restart capture */
- startup_capture(phandle, chandle, format, buffer,
- negotiated.latency, negotiated.channels);
- continue;
- } else if (ret == 0) {
- /* Timed out */
- continue;
- }
-
- if ((r = readbuf(chandle, buffer, negotiated.latency, &frames_in,
- &in_max)) > 0) {
- if (writebuf(phandle, buffer, r, &frames_out) < 0) {
- startup_capture(phandle, chandle, format, buffer,
- negotiated.latency, negotiated.channels);
- }
- } else if (r < 0) {
- startup_capture(phandle, chandle, format, buffer,
- negotiated.latency, negotiated.channels);
- }
+ snd_pcm_wait(chandle, 1000);
}
snd_pcm_drop(chandle);
@@ -451,28 +494,55 @@ int tvtime_alsa_stream(const char *pdevice, const char *cdevice)
snd_pcm_close(phandle);
snd_pcm_close(chandle);
+
+ alsa_is_running = 0;
return 0;
}
struct input_params {
- const char *pdevice;
- const char *cdevice;
+ char *pdevice;
+ char *cdevice;
+ int latency;
};
-void *tvtime_alsa_thread_entry(void *whatever)
+static void *alsa_thread_entry(void *whatever)
{
struct input_params *inputs = (struct input_params *) whatever;
- tvtime_alsa_stream(inputs->pdevice, inputs->cdevice);
+
+ if (verbose)
+ 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");
+
+ free(inputs->pdevice);
+ free(inputs->cdevice);
+ free(inputs);
+
+ return NULL;
}
-int tvtime_alsa_thread_startup(const char *pdevice, const char *cdevice)
+/*************************************************************************
+ Public functions
+ *************************************************************************/
+
+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));
+ if (__error_fp)
+ error_fp = __error_fp;
+ else
+ error_fp = stderr;
+
+ verbose = __verbose;
+
+
if (inputs == NULL) {
- printf("failed allocating memory for ALSA inputs\n");
+ fprintf(error_fp, "alsa: failed allocating memory for inputs\n");
return 0;
}
@@ -484,18 +554,27 @@ int tvtime_alsa_thread_startup(const char *pdevice, const char *cdevice)
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,
- &tvtime_alsa_thread_entry, (void *) inputs);
+ &alsa_thread_entry, (void *) inputs);
return ret;
}
-#ifdef TVTIME_ALSA_DEBUGGING
-/* This allows the alsa_stream.c to be a standalone binary for debugging */
- int main(int argc, char *argv[])
+void alsa_thread_stop(void)
+{
+ stop_alsa = 1;
+}
+
+int alsa_thread_is_running(void)
{
- char *pdevice = "hw:0,0";
- char *cdevice = "hw:1,0";
- tvtime_alsa_stream(pdevice, cdevice);
+ return alsa_is_running;
}
-#endif
diff --git a/src/alsa_stream.h b/src/alsa_stream.h
index 8572c8b..c68fd6d 100644
--- a/src/alsa_stream.h
+++ b/src/alsa_stream.h
@@ -1 +1,5 @@
-int tvtime_alsa_thread_startup(char *pdevice, char *cdevice);
+int alsa_thread_startup(const char *pdevice, const char *cdevice, int latency,
+ FILE *__error_fp,
+ int __verbose);
+void alsa_thread_stop(void);
+int alsa_thread_is_running(void);
diff --git a/src/tvtime.c b/src/tvtime.c
index 75257d1..d9066cc 100644
--- a/src/tvtime.c
+++ b/src/tvtime.c
@@ -1256,8 +1256,10 @@ int tvtime_main( rtctimer_t *rtctimer, int read_stdin, int realtime,
}
/* Setup the ALSA streaming device */
- tvtime_alsa_thread_startup(config_get_alsa_outputdev( ct ),
- config_get_alsa_inputdev( ct ) );
+ alsa_thread_startup(config_get_alsa_outputdev( ct ),
+ config_get_alsa_inputdev( ct ),
+ 30, /* FIXME: Add a var to adjust latency */
+ stderr, verbose );
/* Setup the speedy calls. */
setup_speedy_calls( mm_accel(), verbose );
--
1.7.6.1
--
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