[FFmpeg-devel] [PATCH] lavd/pulse_audio_enc: add buffer length control options
Lukasz Marek
lukasz.m.luki at gmail.com
Sat Nov 23 15:30:01 CET 2013
Add options to control the length of the PulseAudio buffer.
Signed-off-by: Lukasz Marek <lukasz.m.luki at gmail.com>
---
doc/outdevs.texi | 8 ++++++++
libavdevice/pulse_audio_enc.c | 21 +++++++++++++++++++++
libavdevice/version.h | 2 +-
3 files changed, 30 insertions(+), 1 deletion(-)
diff --git a/doc/outdevs.texi b/doc/outdevs.texi
index c737225..0e7309e 100644
--- a/doc/outdevs.texi
+++ b/doc/outdevs.texi
@@ -164,6 +164,14 @@ by default it is set to the specified output name.
Specify the device to use. Default device is used when not provided.
List of output devices can be obtained with command @command{pactl list sinks}.
+ at item buffer_length
+ at item buffer_duration
+Controls the length of the PulseAudio buffer. Small buffer gives more control,
+but requires more frequent updates.
+buffer_length specifies length in bytes while buffer_duration specifies length in miliseconds.
+When both options are provided then higher value is used.
+By default PulseAudio set buffer length to around 2 seconds.
+
@end table
@subsection Examples
diff --git a/libavdevice/pulse_audio_enc.c b/libavdevice/pulse_audio_enc.c
index a2abc4a..0115862 100644
--- a/libavdevice/pulse_audio_enc.c
+++ b/libavdevice/pulse_audio_enc.c
@@ -35,6 +35,8 @@ typedef struct PulseData {
const char *device;
pa_simple *pa;
int64_t timestamp;
+ unsigned buffer_length;
+ unsigned buffer_duration;
} PulseData;
static av_cold int pulse_write_header(AVFormatContext *h)
@@ -59,6 +61,23 @@ static av_cold int pulse_write_header(AVFormatContext *h)
stream_name = "Playback";
}
+ if (s->buffer_duration) {
+ int64_t bytes = s->buffer_duration;
+ bytes *= st->codec->channels * st->codec->sample_rate *
+ av_get_bytes_per_sample(st->codec->sample_fmt);
+ bytes /= 1000;
+ attr.tlength = FFMAX(s->buffer_length, av_clip64_c(bytes, 0, 0xFFFFFFFE));
+ av_log(s, AV_LOG_DEBUG,
+ "Buffer duration: %ums recalculated into %"PRId64" bytes buffer.\n",
+ s->buffer_duration, bytes);
+ av_log(s, AV_LOG_DEBUG, "Real buffer length is %u bytes\n", attr.tlength);
+ }
+ else if (s->buffer_length) {
+ attr.tlength = s->buffer_length;
+ if (s->buffer_duration)
+ av_log(s, AV_LOG_WARNING, "buffer_duration parameter is ignored.\n");
+ }
+
ss.format = ff_codec_id_to_pulse_format(st->codec->codec_id);
ss.rate = st->codec->sample_rate;
ss.channels = st->codec->channels;
@@ -142,6 +161,8 @@ static const AVOption options[] = {
{ "name", "set application name", OFFSET(name), AV_OPT_TYPE_STRING, {.str = LIBAVFORMAT_IDENT}, 0, 0, E },
{ "stream_name", "set stream description", OFFSET(stream_name), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E },
{ "device", "set device name", OFFSET(device), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E },
+ { "buffer_length", "set buffer length in bytes", OFFSET(buffer_length), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 0xFFFFFFFE, E },
+ { "buffer_duration", "set buffer length in msecs", OFFSET(buffer_duration), AV_OPT_TYPE_INT, {.i64 = 0}, 0, UINT_MAX, E },
{ NULL }
};
diff --git a/libavdevice/version.h b/libavdevice/version.h
index 4f4ec99..8e3ff7f 100644
--- a/libavdevice/version.h
+++ b/libavdevice/version.h
@@ -29,7 +29,7 @@
#define LIBAVDEVICE_VERSION_MAJOR 55
#define LIBAVDEVICE_VERSION_MINOR 5
-#define LIBAVDEVICE_VERSION_MICRO 100
+#define LIBAVDEVICE_VERSION_MICRO 101
#define LIBAVDEVICE_VERSION_INT AV_VERSION_INT(LIBAVDEVICE_VERSION_MAJOR, \
LIBAVDEVICE_VERSION_MINOR, \
--
1.7.10.4
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