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output example: use the new AVFrame API to allocate audio frames

This commit is contained in:
Anton Khirnov 2014-06-24 07:51:18 +02:00
parent ac85f631c9
commit 5e7b125b6a
1 changed files with 24 additions and 19 deletions
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43
doc/examples/output.c
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@ -59,7 +59,6 @@ typedef struct OutputStream {
/* audio output */
static float t, tincr, tincr2;
static int16_t *samples;
static int audio_input_frame_size;
/*
@ -122,20 +121,24 @@ static void open_audio(AVFormatContext *oc, AVStream *st)
audio_input_frame_size = 10000;
else
audio_input_frame_size = c->frame_size;
samples = av_malloc(audio_input_frame_size *
av_get_bytes_per_sample(c->sample_fmt) *
c->channels);
}
/* Prepare a 16 bit dummy audio frame of 'frame_size' samples and
* 'nb_channels' channels. */
static void get_audio_frame(int16_t *samples, int frame_size, int nb_channels)
static void get_audio_frame(AVFrame *frame, int nb_channels)
{
int j, i, v;
int16_t *q;
int j, i, v, ret;
int16_t *q = (int16_t*)frame->data[0];
q = samples;
for (j = 0; j < frame_size; j++) {
/* when we pass a frame to the encoder, it may keep a reference to it
* internally;
* make sure we do not overwrite it here
*/
ret = av_frame_make_writable(frame);
if (ret < 0)
exit(1);
for (j = 0; j < frame->nb_samples; j++) {
v = (int)(sin(t) * 10000);
for (i = 0; i < nb_channels; i++)
*q++ = v;
@ -149,18 +152,22 @@ static void write_audio_frame(AVFormatContext *oc, AVStream *st)
AVCodecContext *c;
AVPacket pkt = { 0 }; // data and size must be 0;
AVFrame *frame = av_frame_alloc();
int got_packet;
int got_packet, ret;
av_init_packet(&pkt);
c = st->codec;
get_audio_frame(samples, audio_input_frame_size, c->channels);
frame->nb_samples = audio_input_frame_size;
avcodec_fill_audio_frame(frame, c->channels, c->sample_fmt,
(uint8_t *)samples,
audio_input_frame_size *
av_get_bytes_per_sample(c->sample_fmt) *
c->channels, 1);
frame->sample_rate = c->sample_rate;
frame->nb_samples = audio_input_frame_size;
frame->format = AV_SAMPLE_FMT_S16;
frame->channel_layout = c->channel_layout;
ret = av_frame_get_buffer(frame, 0);
if (ret < 0) {
fprintf(stderr, "Could not allocate an audio frame.\n");
exit(1);
}
get_audio_frame(frame, c->channels);
avcodec_encode_audio2(c, &pkt, frame, &got_packet);
if (!got_packet)
@ -179,8 +186,6 @@ static void write_audio_frame(AVFormatContext *oc, AVStream *st)
static void close_audio(AVFormatContext *oc, AVStream *st)
{
avcodec_close(st->codec);
av_free(samples);
}
/**************************************************************/