+static int opt_attach(OptionsContext *o, const char *opt, const char *arg)
+{
+ o->attachments = grow_array(o->attachments, sizeof(*o->attachments),
+ &o->nb_attachments, o->nb_attachments + 1);
+ o->attachments[o->nb_attachments - 1] = arg;
+ return 0;
+}
+
+static int opt_map_channel(OptionsContext *o, const char *opt, const char *arg)
+{
+ int n;
+ AVStream *st;
+ AudioChannelMap *m;
+
+ o->audio_channel_maps =
+ grow_array(o->audio_channel_maps, sizeof(*o->audio_channel_maps),
+ &o->nb_audio_channel_maps, o->nb_audio_channel_maps + 1);
+ m = &o->audio_channel_maps[o->nb_audio_channel_maps - 1];
+
+ /* muted channel syntax */
+ n = sscanf(arg, "%d:%d.%d", &m->channel_idx, &m->ofile_idx, &m->ostream_idx);
+ if ((n == 1 || n == 3) && m->channel_idx == -1) {
+ m->file_idx = m->stream_idx = -1;
+ if (n == 1)
+ m->ofile_idx = m->ostream_idx = -1;
+ return 0;
+ }
+
+ /* normal syntax */
+ n = sscanf(arg, "%d.%d.%d:%d.%d",
+ &m->file_idx, &m->stream_idx, &m->channel_idx,
+ &m->ofile_idx, &m->ostream_idx);
+
+ if (n != 3 && n != 5) {
+ av_log(NULL, AV_LOG_FATAL, "Syntax error, mapchan usage: "
+ "[file.stream.channel|-1][:syncfile:syncstream]\n");
+ exit_program(1);
+ }
+
+ if (n != 5) // only file.stream.channel specified
+ m->ofile_idx = m->ostream_idx = -1;
+
+ /* check input */
+ if (m->file_idx < 0 || m->file_idx >= nb_input_files) {
+ av_log(NULL, AV_LOG_FATAL, "mapchan: invalid input file index: %d\n",
+ m->file_idx);
+ exit_program(1);
+ }
+ if (m->stream_idx < 0 ||
+ m->stream_idx >= input_files[m->file_idx].nb_streams) {
+ av_log(NULL, AV_LOG_FATAL, "mapchan: invalid input file stream index #%d.%d\n",
+ m->file_idx, m->stream_idx);
+ exit_program(1);
+ }
+ st = input_files[m->file_idx].ctx->streams[m->stream_idx];
+ if (st->codec->codec_type != AVMEDIA_TYPE_AUDIO) {
+ av_log(NULL, AV_LOG_FATAL, "mapchan: stream #%d.%d is not an audio stream.\n",
+ m->file_idx, m->stream_idx);
+ exit_program(1);
+ }
+ if (m->channel_idx < 0 || m->channel_idx >= st->codec->channels) {
+ av_log(NULL, AV_LOG_FATAL, "mapchan: invalid audio channel #%d.%d.%d\n",
+ m->file_idx, m->stream_idx, m->channel_idx);
+ exit_program(1);
+ }
+ return 0;
+}
+