ffmpeg/libavdevice/oss_audio_enc.c

   1 /*
   2  * Linux audio grab interface
   3  * Copyright (c) 2000, 2001 Fabrice Bellard
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "config.h"
  23
  24 #if HAVE_SOUNDCARD_H
  25 #include <soundcard.h>
  26 #else
  27 #include <sys/soundcard.h>
  28 #endif
  29
  30 #if HAVE_UNISTD_H
  31 #include <unistd.h>
  32 #endif
  33 #include <fcntl.h>
  34 #include <sys/ioctl.h>
  35
  36 #include "libavutil/internal.h"
  37
  38 #include "libavcodec/avcodec.h"
  39
  40 #include "avdevice.h"
  41 #include "libavformat/internal.h"
  42
  43 #include "oss_audio.h"
  44
  45 static int audio_write_header(AVFormatContext *s1)
  46 {
  47     OSSAudioData *s = s1->priv_data;
  48     AVStream *st;
  49     int ret;
  50
  51     st = s1->streams[0];
  52     s->sample_rate = st->codec->sample_rate;
  53     s->channels = st->codec->channels;
  54     ret = ff_oss_audio_open(s1, 1, s1->filename);
  55     if (ret < 0) {
  56         return AVERROR(EIO);
  57     } else {
  58         return 0;
  59     }
  60 }
  61
  62 static int audio_write_packet(AVFormatContext *s1, AVPacket *pkt)
  63 {
  64     OSSAudioData *s = s1->priv_data;
  65     int len, ret;
  66     int size= pkt->size;
  67     uint8_t *buf= pkt->data;
  68
  69     while (size > 0) {
  70         len = FFMIN(OSS_AUDIO_BLOCK_SIZE - s->buffer_ptr, size);
  71         memcpy(s->buffer + s->buffer_ptr, buf, len);
  72         s->buffer_ptr += len;
  73         if (s->buffer_ptr >= OSS_AUDIO_BLOCK_SIZE) {
  74             for(;;) {
  75                 ret = write(s->fd, s->buffer, OSS_AUDIO_BLOCK_SIZE);
  76                 if (ret > 0)
  77                     break;
  78                 if (ret < 0 && (errno != EAGAIN && errno != EINTR))
  79                     return AVERROR(EIO);
  80             }
  81             s->buffer_ptr = 0;
  82         }
  83         buf += len;
  84         size -= len;
  85     }
  86     return 0;
  87 }
  88
  89 static int audio_write_trailer(AVFormatContext *s1)
  90 {
  91     OSSAudioData *s = s1->priv_data;
  92
  93     ff_oss_audio_close(s);
  94     return 0;
  95 }
  96
  97 static const AVClass oss_muxer_class = {
  98     .class_name     = "OSS muxer",
  99     .item_name      = av_default_item_name,
 100     .version        = LIBAVUTIL_VERSION_INT,
 101     .category       = AV_CLASS_CATEGORY_DEVICE_AUDIO_OUTPUT,
 102 };
 103
 104 AVOutputFormat ff_oss_muxer = {
 105     .name           = "oss",
 106     .long_name      = NULL_IF_CONFIG_SMALL("OSS (Open Sound System) playback"),
 107     .priv_data_size = sizeof(OSSAudioData),
 108     /* XXX: we make the assumption that the soundcard accepts this format */
 109     /* XXX: find better solution with "preinit" method, needed also in
 110        other formats */
 111     .audio_codec    = AV_NE(AV_CODEC_ID_PCM_S16BE, AV_CODEC_ID_PCM_S16LE),
 112     .video_codec    = AV_CODEC_ID_NONE,
 113     .write_header   = audio_write_header,
 114     .write_packet   = audio_write_packet,
 115     .write_trailer  = audio_write_trailer,
 116     .flags          = AVFMT_NOFILE,
 117     .priv_class     = &oss_muxer_class,
 118 };