diff options
Diffstat (limited to 'doc/examples/muxing.c')
-rw-r--r-- | doc/examples/muxing.c | 86 |
1 files changed, 40 insertions, 46 deletions
diff --git a/doc/examples/muxing.c b/doc/examples/muxing.c index 5eb0135499..b6958a5e0b 100644 --- a/doc/examples/muxing.c +++ b/doc/examples/muxing.c @@ -56,6 +56,9 @@ typedef struct OutputStream { AVFrame *frame; AVFrame *tmp_frame; + + float t, tincr, tincr2; + int audio_input_frame_size; } OutputStream; static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt) @@ -81,9 +84,9 @@ static int write_frame(AVFormatContext *fmt_ctx, const AVRational *time_base, AV } /* Add an output stream. */ -static AVStream *add_stream(OutputStream *ost, AVFormatContext *oc, - AVCodec **codec, - enum AVCodecID codec_id) +static void add_stream(OutputStream *ost, AVFormatContext *oc, + AVCodec **codec, + enum AVCodecID codec_id) { AVCodecContext *c; @@ -147,27 +150,21 @@ static AVStream *add_stream(OutputStream *ost, AVFormatContext *oc, /* Some formats want stream headers to be separate. */ if (oc->oformat->flags & AVFMT_GLOBALHEADER) c->flags |= CODEC_FLAG_GLOBAL_HEADER; - - return ost->st; } /**************************************************************/ /* audio output */ -static float t, tincr, tincr2; - -static int src_nb_samples; - int samples_count; struct SwrContext *swr_ctx = NULL; -static void open_audio(AVFormatContext *oc, AVCodec *codec, AVStream *st) +static void open_audio(AVFormatContext *oc, AVCodec *codec, OutputStream *ost) { AVCodecContext *c; int ret; - c = st->codec; + c = ost->st->codec; /* open it */ ret = avcodec_open2(c, codec, NULL); @@ -177,15 +174,15 @@ static void open_audio(AVFormatContext *oc, AVCodec *codec, AVStream *st) } /* init signal generator */ - t = 0; - tincr = 2 * M_PI * 110.0 / c->sample_rate; + ost->t = 0; + ost->tincr = 2 * M_PI * 110.0 / c->sample_rate; /* increment frequency by 110 Hz per second */ - tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate; + ost->tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate; if (c->codec->capabilities & CODEC_CAP_VARIABLE_FRAME_SIZE) - src_nb_samples = 10000; + ost->audio_input_frame_size = 10000; else - src_nb_samples = c->frame_size; + ost->audio_input_frame_size = c->frame_size; /* create resampler context */ if (c->sample_fmt != AV_SAMPLE_FMT_S16) { @@ -213,7 +210,7 @@ static void open_audio(AVFormatContext *oc, AVCodec *codec, AVStream *st) /* Prepare a 16 bit dummy audio frame of 'frame_size' samples and * 'nb_channels' channels. */ -static void get_audio_frame(AVFrame *frame, int nb_channels) +static void get_audio_frame(OutputStream *ost, AVFrame *frame, int nb_channels) { int j, i, v, ret; int16_t *q = (int16_t*)frame->data[0]; @@ -227,15 +224,15 @@ static void get_audio_frame(AVFrame *frame, int nb_channels) exit(1); for (j = 0; j < frame->nb_samples; j++) { - v = (int)(sin(t) * 10000); + v = (int)(sin(ost->t) * 10000); for (i = 0; i < nb_channels; i++) *q++ = v; - t += tincr; - tincr += tincr2; + ost->t += ost->tincr; + ost->tincr += ost->tincr2; } } -static void write_audio_frame(AVFormatContext *oc, AVStream *st, int flush) +static void write_audio_frame(AVFormatContext *oc, OutputStream *ost, int flush) { AVCodecContext *c; AVPacket pkt = { 0 }; // data and size must be 0; @@ -244,11 +241,11 @@ static void write_audio_frame(AVFormatContext *oc, AVStream *st, int flush) int dst_nb_samples; av_init_packet(&pkt); - c = st->codec; + c = ost->st->codec; if (!flush) { frame->sample_rate = c->sample_rate; - frame->nb_samples = src_nb_samples; + frame->nb_samples = ost->audio_input_frame_size; frame->format = AV_SAMPLE_FMT_S16; frame->channel_layout = c->channel_layout; ret = av_frame_get_buffer(frame, 0); @@ -257,14 +254,14 @@ static void write_audio_frame(AVFormatContext *oc, AVStream *st, int flush) exit(1); } - get_audio_frame(frame, c->channels); + get_audio_frame(ost, frame, c->channels); /* convert samples from native format to destination codec format, using the resampler */ if (swr_ctx) { AVFrame *tmp_frame = av_frame_alloc(); /* compute destination number of samples */ - dst_nb_samples = av_rescale_rnd(swr_get_delay(swr_ctx, c->sample_rate) + src_nb_samples, + dst_nb_samples = av_rescale_rnd(swr_get_delay(swr_ctx, c->sample_rate) + ost->audio_input_frame_size, c->sample_rate, c->sample_rate, AV_ROUND_UP); tmp_frame->sample_rate = c->sample_rate; tmp_frame->nb_samples = dst_nb_samples; @@ -279,7 +276,7 @@ static void write_audio_frame(AVFormatContext *oc, AVStream *st, int flush) /* convert to destination format */ ret = swr_convert(swr_ctx, tmp_frame->data, dst_nb_samples, - (const uint8_t **)frame->data, src_nb_samples); + (const uint8_t **)frame->data, ost->audio_input_frame_size); if (ret < 0) { fprintf(stderr, "Error while converting\n"); exit(1); @@ -287,7 +284,7 @@ static void write_audio_frame(AVFormatContext *oc, AVStream *st, int flush) av_frame_free(&frame); frame = tmp_frame; } else { - dst_nb_samples = src_nb_samples; + dst_nb_samples = ost->audio_input_frame_size; } frame->nb_samples = dst_nb_samples; @@ -307,7 +304,7 @@ static void write_audio_frame(AVFormatContext *oc, AVStream *st, int flush) return; } - ret = write_frame(oc, &c->time_base, st, &pkt); + ret = write_frame(oc, &c->time_base, ost->st, &pkt); if (ret < 0) { fprintf(stderr, "Error while writing audio frame: %s\n", av_err2str(ret)); @@ -315,9 +312,9 @@ static void write_audio_frame(AVFormatContext *oc, AVStream *st, int flush) } } -static void close_audio(AVFormatContext *oc, AVStream *st) +static void close_audio(AVFormatContext *oc, OutputStream *ost) { - avcodec_close(st->codec); + avcodec_close(ost->st->codec); } /**************************************************************/ @@ -492,15 +489,14 @@ static void close_video(AVFormatContext *oc, OutputStream *ost) int main(int argc, char **argv) { - OutputStream video_st; + OutputStream video_st, audio_st; const char *filename; AVOutputFormat *fmt; AVFormatContext *oc; - AVStream *audio_st; AVCodec *audio_codec, *video_codec; double audio_time, video_time; int flush, ret; - int have_video = 0; + int have_video = 0, have_audio = 0; /* Initialize libavcodec, and register all codecs and formats. */ av_register_all(); @@ -531,15 +527,13 @@ int main(int argc, char **argv) /* Add the audio and video streams using the default format codecs * and initialize the codecs. */ - audio_st = NULL; - if (fmt->video_codec != AV_CODEC_ID_NONE) { add_stream(&video_st, oc, &video_codec, fmt->video_codec); have_video = 1; } if (fmt->audio_codec != AV_CODEC_ID_NONE) { - OutputStream dummy; - audio_st = add_stream(&dummy, oc, &audio_codec, fmt->audio_codec); + add_stream(&audio_st, oc, &audio_codec, fmt->audio_codec); + have_audio = 1; } /* Now that all the parameters are set, we can open the audio and @@ -547,8 +541,8 @@ int main(int argc, char **argv) if (have_video) open_video(oc, video_codec, &video_st); - if (audio_st) - open_audio(oc, audio_codec, audio_st); + if (have_audio) + open_audio(oc, audio_codec, &audio_st); av_dump_format(oc, 0, filename, 1); @@ -571,20 +565,20 @@ int main(int argc, char **argv) } flush = 0; - while ((have_video && !video_is_eof) || (audio_st && !audio_is_eof)) { + while ((have_video && !video_is_eof) || (have_audio && !audio_is_eof)) { /* Compute current audio and video time. */ - audio_time = (audio_st && !audio_is_eof) ? audio_st->pts.val * av_q2d(audio_st->time_base) : INFINITY; + audio_time = (have_audio && !audio_is_eof) ? audio_st.st->pts.val * av_q2d(audio_st.st->time_base) : INFINITY; video_time = (have_video && !video_is_eof) ? video_st.st->pts.val * av_q2d(video_st.st->time_base) : INFINITY; if (!flush && - (!audio_st || audio_time >= STREAM_DURATION) && + (!have_audio || audio_time >= STREAM_DURATION) && (!have_video || video_time >= STREAM_DURATION)) { flush = 1; } /* write interleaved audio and video frames */ - if (audio_st && !audio_is_eof && audio_time <= video_time) { - write_audio_frame(oc, audio_st, flush); + if (have_audio && !audio_is_eof && audio_time <= video_time) { + write_audio_frame(oc, &audio_st, flush); } else if (have_video && !video_is_eof && video_time < audio_time) { write_video_frame(oc, &video_st, flush); } @@ -599,8 +593,8 @@ int main(int argc, char **argv) /* Close each codec. */ if (have_video) close_video(oc, &video_st); - if (audio_st) - close_audio(oc, audio_st); + if (have_audio) + close_audio(oc, &audio_st); if (!(fmt->flags & AVFMT_NOFILE)) /* Close the output file. */ |