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ffmpeg.wasm-core
Commit 11991a7d authored by Michael Niedermayer's avatar Michael Niedermayer
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Merge commit '5e7b125b' 

* commit '5e7b125b':
  output example: use the new AVFrame API to allocate audio frames

Conflicts:
	doc/examples/muxing.c
Merged-by: 's avatarMichael Niedermayer <michaelni@gmx.at>
parents a1c46355 5e7b125b
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Showing with 47 additions and 69 deletions
doc/examples/muxing.c
View file @ 11991a7d
......@@ -156,15 +156,8 @@ static AVStream *add_stream(OutputStream *ost, AVFormatContext *oc,
static float t, tincr, tincr2;
AVFrame *audio_frame;
static uint8_t **src_samples_data;
static int src_samples_linesize;
static int src_nb_samples;
static int max_dst_nb_samples;
uint8_t **dst_samples_data;
int dst_samples_linesize;
int dst_samples_size;
int samples_count;
struct SwrContext *swr_ctx = NULL;
......@@ -176,13 +169,6 @@ static void open_audio(AVFormatContext *oc, AVCodec *codec, AVStream *st)
c = st->codec;
/* allocate and init a re-usable frame */
audio_frame = av_frame_alloc();
if (!audio_frame) {
fprintf(stderr, "Could not allocate audio frame\n");
exit(1);
}
/* open it */
ret = avcodec_open2(c, codec, NULL);
if (ret < 0) {
......@@ -196,20 +182,10 @@ static void open_audio(AVFormatContext *oc, AVCodec *codec, AVStream *st)
/* increment frequency by 110 Hz per second */
tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate;
src_nb_samples = c->codec->capabilities & CODEC_CAP_VARIABLE_FRAME_SIZE ?
10000 : c->frame_size;
ret = av_samples_alloc_array_and_samples(&src_samples_data, &src_samples_linesize, c->channels,
src_nb_samples, AV_SAMPLE_FMT_S16, 0);
if (ret < 0) {
fprintf(stderr, "Could not allocate source samples\n");
exit(1);
}
/* compute the number of converted samples: buffering is avoided
* ensuring that the output buffer will contain at least all the
* converted input samples */
max_dst_nb_samples = src_nb_samples;
if (c->codec->capabilities & CODEC_CAP_VARIABLE_FRAME_SIZE)
src_nb_samples = 10000;
else
src_nb_samples = c->frame_size;
/* create resampler context */
if (c->sample_fmt != AV_SAMPLE_FMT_S16) {
......@@ -232,29 +208,25 @@ static void open_audio(AVFormatContext *oc, AVCodec *codec, AVStream *st)
fprintf(stderr, "Failed to initialize the resampling context\n");
exit(1);
}
ret = av_samples_alloc_array_and_samples(&dst_samples_data, &dst_samples_linesize, c->channels,
max_dst_nb_samples, c->sample_fmt, 0);
if (ret < 0) {
fprintf(stderr, "Could not allocate destination samples\n");
exit(1);
}
} else {
dst_samples_data = src_samples_data;
}
dst_samples_size = av_samples_get_buffer_size(NULL, c->channels, max_dst_nb_samples,
c->sample_fmt, 0);
}
/* 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];
/* 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);
q = samples;
for (j = 0; j < frame_size; j++) {
for (j = 0; j < frame->nb_samples; j++) {
v = (int)(sin(t) * 10000);
for (i = 0; i < nb_channels; i++)
*q++ = v;
......@@ -267,50 +239,63 @@ static void write_audio_frame(AVFormatContext *oc, AVStream *st, int flush)
{
AVCodecContext *c;
AVPacket pkt = { 0 }; // data and size must be 0;
int got_packet, ret, dst_nb_samples;
AVFrame *frame = av_frame_alloc();
int got_packet, ret;
int dst_nb_samples;
av_init_packet(&pkt);
c = st->codec;
if (!flush) {
get_audio_frame((int16_t *)src_samples_data[0], src_nb_samples, c->channels);
frame->sample_rate = c->sample_rate;
frame->nb_samples = src_nb_samples;
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);
/* 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,
c->sample_rate, c->sample_rate, AV_ROUND_UP);
if (dst_nb_samples > max_dst_nb_samples) {
av_free(dst_samples_data[0]);
ret = av_samples_alloc(dst_samples_data, &dst_samples_linesize, c->channels,
dst_nb_samples, c->sample_fmt, 0);
if (ret < 0)
exit(1);
max_dst_nb_samples = dst_nb_samples;
dst_samples_size = av_samples_get_buffer_size(NULL, c->channels, dst_nb_samples,
c->sample_fmt, 0);
tmp_frame->sample_rate = c->sample_rate;
tmp_frame->nb_samples = dst_nb_samples;
tmp_frame->format = c->sample_fmt;
tmp_frame->channel_layout = c->channel_layout;
ret = av_frame_get_buffer(tmp_frame, 0);
if (ret < 0) {
fprintf(stderr, "Could not allocate an audio frame.\n");
exit(1);
}
/* convert to destination format */
ret = swr_convert(swr_ctx,
dst_samples_data, dst_nb_samples,
(const uint8_t **)src_samples_data, src_nb_samples);
tmp_frame->data, dst_nb_samples,
(const uint8_t **)frame->data, src_nb_samples);
if (ret < 0) {
fprintf(stderr, "Error while converting\n");
exit(1);
}
av_frame_free(&frame);
frame = tmp_frame;
} else {
dst_nb_samples = src_nb_samples;
}
audio_frame->nb_samples = dst_nb_samples;
audio_frame->pts = av_rescale_q(samples_count, (AVRational){1, c->sample_rate}, c->time_base);
avcodec_fill_audio_frame(audio_frame, c->channels, c->sample_fmt,
dst_samples_data[0], dst_samples_size, 0);
frame->nb_samples = dst_nb_samples;
frame->pts = av_rescale_q(samples_count, (AVRational){1, c->sample_rate}, c->time_base);
samples_count += dst_nb_samples;
}
ret = avcodec_encode_audio2(c, &pkt, flush ? NULL : audio_frame, &got_packet);
ret = avcodec_encode_audio2(c, &pkt, flush ? NULL : frame, &got_packet);
if (ret < 0) {
fprintf(stderr, "Error encoding audio frame: %s\n", av_err2str(ret));
exit(1);
......@@ -333,13 +318,6 @@ static void write_audio_frame(AVFormatContext *oc, AVStream *st, int flush)
static void close_audio(AVFormatContext *oc, AVStream *st)
{
avcodec_close(st->codec);
if (dst_samples_data != src_samples_data) {
av_free(dst_samples_data[0]);
av_free(dst_samples_data);
}
av_free(src_samples_data[0]);
av_free(src_samples_data);
av_frame_free(&audio_frame);
}
/**************************************************************/
......
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