ffmpeg/libavdevice/sndio.c

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/*
* sndio grab interface
* Copyright (c) 2010 Jacob Meuser
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdint.h>
#include <sndio.h>
#include "libavutil/internal.h"
#include "libavutil/opt.h"
#include "libavutil/time.h"
#include "libavformat/avformat.h"
#include "libavformat/internal.h"
typedef struct SndioData {
AVClass *class;
struct sio_hdl *hdl;
enum AVCodecID codec_id;
int64_t hwpos;
int64_t softpos;
uint8_t *buffer;
int bps;
int buffer_size;
int buffer_offset;
int channels;
int sample_rate;
} SndioData;
static inline void movecb(void *addr, int delta)
{
SndioData *s = addr;
s->hwpos += delta * s->channels * s->bps;
}
static av_cold int sndio_open(AVFormatContext *s1, int is_output,
const char *audio_device)
{
SndioData *s = s1->priv_data;
struct sio_hdl *hdl;
struct sio_par par;
hdl = sio_open(audio_device, is_output ? SIO_PLAY : SIO_REC, 0);
if (!hdl) {
av_log(s1, AV_LOG_ERROR, "Could not open sndio device\n");
return AVERROR(EIO);
}
sio_initpar(&par);
par.bits = 16;
par.sig = 1;
par.le = SIO_LE_NATIVE;
if (is_output)
par.pchan = s->channels;
else
par.rchan = s->channels;
par.rate = s->sample_rate;
if (!sio_setpar(hdl, &par) || !sio_getpar(hdl, &par)) {
av_log(s1, AV_LOG_ERROR, "Impossible to set sndio parameters, "
"channels: %d sample rate: %d\n", s->channels, s->sample_rate);
goto fail;
}
if (par.bits != 16 || par.sig != 1 ||
(is_output && (par.pchan != s->channels)) ||
(!is_output && (par.rchan != s->channels)) ||
(par.rate != s->sample_rate)) {
av_log(s1, AV_LOG_ERROR, "Could not set appropriate sndio parameters, "
"channels: %d sample rate: %d\n", s->channels, s->sample_rate);
goto fail;
}
s->buffer_size = par.round * par.bps *
(is_output ? par.pchan : par.rchan);
if (is_output) {
s->buffer = av_malloc(s->buffer_size);
if (!s->buffer) {
av_log(s1, AV_LOG_ERROR, "Could not allocate buffer\n");
goto fail;
}
}
s->codec_id = par.le ? AV_CODEC_ID_PCM_S16LE : AV_CODEC_ID_PCM_S16BE;
s->channels = is_output ? par.pchan : par.rchan;
s->sample_rate = par.rate;
s->bps = par.bps;
sio_onmove(hdl, movecb, s);
if (!sio_start(hdl)) {
av_log(s1, AV_LOG_ERROR, "Could not start sndio\n");
goto fail;
}
s->hdl = hdl;
return 0;
fail:
av_freep(&s->buffer);
if (hdl)
sio_close(hdl);
return AVERROR(EIO);
}
static av_cold int audio_read_header(AVFormatContext *s1)
{
SndioData *s = s1->priv_data;
AVStream *st;
int ret;
st = avformat_new_stream(s1, NULL);
if (!st)
return AVERROR(ENOMEM);
ret = sndio_open(s1, 0, s1->filename);
if (ret < 0)
return ret;
/* take real parameters */
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->codec_id = s->codec_id;
st->codecpar->sample_rate = s->sample_rate;
st->codecpar->channels = s->channels;
avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
return 0;
}
static int audio_read_packet(AVFormatContext *s1, AVPacket *pkt)
{
SndioData *s = s1->priv_data;
int64_t bdelay, cur_time;
int ret;
if ((ret = av_new_packet(pkt, s->buffer_size)) < 0)
return ret;
ret = sio_read(s->hdl, pkt->data, pkt->size);
if (ret == 0 || sio_eof(s->hdl)) {
av_packet_unref(pkt);
return AVERROR_EOF;
}
pkt->size = ret;
s->softpos += ret;
/* compute pts of the start of the packet */
cur_time = av_gettime();
bdelay = ret + s->hwpos - s->softpos;
/* convert to pts */
pkt->pts = cur_time - ((bdelay * 1000000) /
(s->bps * s->channels * s->sample_rate));
return 0;
}
static av_cold int audio_read_close(AVFormatContext *s1)
{
SndioData *s = s1->priv_data;
av_freep(&s->buffer);
if (s->hdl)
sio_close(s->hdl);
return 0;
}
static const AVOption options[] = {
{ "sample_rate", "", offsetof(SndioData, sample_rate), AV_OPT_TYPE_INT, {.i64 = 48000}, 1, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
{ "channels", "", offsetof(SndioData, channels), AV_OPT_TYPE_INT, {.i64 = 2}, 1, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
{ NULL },
};
static const AVClass sndio_demuxer_class = {
.class_name = "sndio indev",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
AVInputFormat ff_sndio_demuxer = {
.name = "sndio",
.long_name = NULL_IF_CONFIG_SMALL("sndio audio capture"),
.priv_data_size = sizeof(SndioData),
.read_header = audio_read_header,
.read_packet = audio_read_packet,
.read_close = audio_read_close,
.flags = AVFMT_NOFILE,
.priv_class = &sndio_demuxer_class,
};