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rtpengine/recording-daemon/resample.c

115 lines
3.5 KiB

#include "resample.h"
#include <glib.h>
#include <libavfilter/avfilter.h>
#include <libavfilter/buffersrc.h>
#include <libavfilter/buffersink.h>
#include <libavutil/channel_layout.h>
#include <libavutil/mathematics.h>
#include <inttypes.h>
#include <libavresample/avresample.h>
#include <libavutil/opt.h>
#include <libavutil/frame.h>
#include "log.h"
#include "types.h"
AVFrame *resample_frame(resample_t *resample, AVFrame *frame, const format_t *to_format) {
const char *err;
int errcode = 0;
uint64_t to_channel_layout = av_get_default_channel_layout(to_format->channels);
if (frame->format != to_format->format)
goto resample;
if (frame->sample_rate != to_format->clockrate)
goto resample;
if (frame->channel_layout != to_channel_layout)
goto resample;
return av_frame_clone(frame);
resample:
if (G_UNLIKELY(!resample->avresample)) {
resample->avresample = avresample_alloc_context();
err = "failed to alloc resample context";
if (!resample->avresample)
goto err;
#if LIBAVUTIL_VERSION_INT >= AV_VERSION_INT(54, 31, 0)
if (!frame->channel_layout)
frame->channel_layout = av_get_default_channel_layout(
av_frame_get_channels(frame));
#endif
err = "failed to set resample option";
if ((errcode = av_opt_set_int(resample->avresample, "in_channel_layout",
frame->channel_layout, 0)))
goto err;
if ((errcode = av_opt_set_int(resample->avresample, "in_sample_fmt",
frame->format, 0)))
goto err;
if ((errcode = av_opt_set_int(resample->avresample, "in_sample_rate",
frame->sample_rate, 0)))
goto err;
if ((errcode = av_opt_set_int(resample->avresample, "out_channel_layout",
to_channel_layout, 0)))
goto err;
if ((errcode = av_opt_set_int(resample->avresample, "out_sample_fmt",
to_format->format, 0)))
goto err;
if ((errcode = av_opt_set_int(resample->avresample, "out_sample_rate",
to_format->clockrate, 0)))
goto err;
// av_opt_set_int(dec->avresample, "internal_sample_fmt", AV_SAMPLE_FMT_FLTP, 0); // ?
err = "failed to init resample context";
if ((errcode = avresample_open(resample->avresample)) < 0)
goto err;
}
// get a large enough buffer for resampled audio - this should be enough so we don't
// have to loop
int dst_samples = avresample_available(resample->avresample) +
av_rescale_rnd(avresample_get_delay(resample->avresample) + frame->nb_samples,
to_format->clockrate, frame->sample_rate, AV_ROUND_UP);
AVFrame *swr_frame = av_frame_alloc();
err = "failed to alloc resampling frame";
if (!swr_frame)
goto err;
av_frame_copy_props(swr_frame, frame);
swr_frame->format = to_format->format;
swr_frame->channel_layout = to_channel_layout;
swr_frame->nb_samples = dst_samples;
swr_frame->sample_rate = to_format->clockrate;
err = "failed to get resample buffers";
if ((errcode = av_frame_get_buffer(swr_frame, 0)) < 0)
goto err;
swr_frame->nb_samples = dst_samples;
int ret_samples = avresample_convert(resample->avresample, swr_frame->extended_data,
swr_frame->linesize[0], dst_samples,
frame->extended_data,
frame->linesize[0], frame->nb_samples);
err = "failed to resample audio";
if ((errcode = ret_samples) < 0)
goto err;
swr_frame->nb_samples = ret_samples;
swr_frame->pts = av_rescale(frame->pts, to_format->clockrate, frame->sample_rate);
return swr_frame;
err:
ilog(LOG_ERR, "Error resampling: %s (code %i)", err, errcode);
resample_shutdown(resample);
return NULL;
}
void resample_shutdown(resample_t *resample) {
avresample_free(&resample->avresample);
}