sndio_enc.c

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/*
 * sndio play and grab interface
 * Copyright (c) 2010 Jacob Meuser
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg 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.
 *
 * FFmpeg 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 FFmpeg; 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 "libavformat/mux.h"
 
#include "libavdevice/avdevice.h"
#include "libavdevice/sndio.h"
 
static av_cold int audio_write_header(AVFormatContext *s1)
{
    SndioData *s = s1->priv_data;
    AVStream *st;
    int ret;
 
    st             = s1->streams[0];
    s->sample_rate = st->codecpar->sample_rate;
    s->channels    = st->codecpar->ch_layout.nb_channels;
 
    ret = ff_sndio_open(s1, 1, s1->url);
 
    return ret;
}
 
static int audio_write_packet(AVFormatContext *s1, AVPacket *pkt)
{
    SndioData *s = s1->priv_data;
    const uint8_t *buf = pkt->data;
    int size = pkt->size;
    int len, ret;
 
    while (size > 0) {
        len = FFMIN(s->buffer_size - s->buffer_offset, size);
        memcpy(s->buffer + s->buffer_offset, buf, len);
        buf  += len;
        size -= len;
        s->buffer_offset += len;
        if (s->buffer_offset >= s->buffer_size) {
            ret = sio_write(s->hdl, s->buffer, s->buffer_size);
            if (ret == 0 || sio_eof(s->hdl))
                return AVERROR(EIO);
            s->softpos      += ret;
            s->buffer_offset = 0;
        }
    }
 
    return 0;
}
 
static int audio_write_trailer(AVFormatContext *s1)
{
    SndioData *s = s1->priv_data;
 
    sio_write(s->hdl, s->buffer, s->buffer_offset);
 
    ff_sndio_close(s);
 
    return 0;
}
 
static const AVClass sndio_muxer_class = {
    .class_name     = "sndio outdev",
    .item_name      = av_default_item_name,
    .version        = LIBAVUTIL_VERSION_INT,
    .category       = AV_CLASS_CATEGORY_DEVICE_AUDIO_OUTPUT,
};
 
const FFOutputFormat ff_sndio_muxer = {
    .p.name         = "sndio",
    .p.long_name    = NULL_IF_CONFIG_SMALL("sndio audio playback"),
    .priv_data_size = sizeof(SndioData),
    /* XXX: we make the assumption that the soundcard accepts this format */
    /* XXX: find better solution with "preinit" method, needed also in
       other formats */
    .p.audio_codec  = AV_NE(AV_CODEC_ID_PCM_S16BE, AV_CODEC_ID_PCM_S16LE),
    .p.video_codec  = AV_CODEC_ID_NONE,
    .write_header   = audio_write_header,
    .write_packet   = audio_write_packet,
    .write_trailer  = audio_write_trailer,
    .p.flags        = AVFMT_NOFILE,
    .p.priv_class   = &sndio_muxer_class,
};