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Feature: init audio decoder and encoder

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pull/221/head
xufuji456 2 years ago
parent 1f20cb0580
commit be1de1a124
1 changed files with 73 additions and 26 deletions
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  1. 99
      app/src/main/cpp/audio_resample.cpp

99
app/src/main/cpp/audio_resample.cpp
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@ -47,11 +47,56 @@ static int get_format_from_sample_fmt(const char **fmt, enum AVSampleFormat samp
return AVERROR(EINVAL);
}
int init_audio_decoder(AVFormatContext *fmt_ctx, AVCodecContext *codec_ctx) {
AVCodec *codec = avcodec_find_decoder(fmt_ctx->audio_codec_id);
if (!codec) {
ALOGE("can't found codec id=%d\n", fmt_ctx->audio_codec_id);
return -1;
}
codec_ctx = avcodec_alloc_context3(codec);
if (!codec_ctx) {
ALOGE("avcodec_alloc_context3 fail!\n");
return -2;
}
return avcodec_open2(codec_ctx, codec, nullptr);
}
int init_audio_encoder(AVFormatContext *fmt_ctx, AVCodecContext *codec_ctx) {
AVCodec *codec = avcodec_find_encoder(fmt_ctx->audio_codec_id);
if (!codec) {
ALOGE("can't found codec id=%d\n", fmt_ctx->audio_codec_id);
return -1;
}
codec_ctx = avcodec_alloc_context3(codec);
if (!codec_ctx) {
ALOGE("avcodec_alloc_context3 fail!\n");
return -2;
}
return avcodec_open2(codec_ctx, codec, nullptr);
}
int init_audio_muxer(AVFormatContext *fmt_ctx, const char* filename) {
int ret;
avformat_alloc_output_context2(&fmt_ctx, nullptr, nullptr, filename);
av_dump_format(fmt_ctx, 0, filename, 1);
if (!(fmt_ctx->oformat->flags & AVFMT_NOFILE)) {
ret = avio_open(&fmt_ctx->pb, filename, AVIO_FLAG_WRITE);
if (ret < 0) {
ALOGE("Could not open output file %s\n", filename);
return ret;
}
}
/* init muxer, write output file header */
ret = avformat_write_header(fmt_ctx, nullptr);
if (ret < 0) {
ALOGE("Error occurred when opening output file\n");
}
return ret;
}
int resampling(const char *src_filename, const char *dst_filename, int dst_rate)
{
int src_rate = 0;
int src_linesize;
int src_nb_channels;
int src_nb_samples = 0;
int64_t src_ch_layout = AV_CH_LAYOUT_STEREO;
enum AVSampleFormat src_sample_fmt = AV_SAMPLE_FMT_S16;
@ -67,17 +112,24 @@ int resampling(const char *src_filename, const char *dst_filename, int dst_rate)
int ret;
const char *fmt;
AVPacket packet;
AVPacket *opacket;
AVFrame *frame;
int got_frame_ptr;
int got_packet_ptr;
struct SwrContext *swr_ctx;
AVFormatContext *iformat_ctx = nullptr;
AVFormatContext *oformat_ctx = nullptr;
AVCodecContext *icodec_ctx = nullptr;
AVCodecContext *ocodec_ctx = nullptr;
ret = avformat_open_input(&iformat_ctx, src_filename, nullptr, nullptr);
if (ret < 0) {
ALOGE("open input fail, path=%s, ret=%d", src_filename, ret);
goto end;
}
avformat_find_stream_info(iformat_ctx, nullptr);
frame = av_frame_alloc();
opacket = av_packet_alloc();
/* create resample context */
swr_ctx = swr_alloc();
@ -102,9 +154,6 @@ int resampling(const char *src_filename, const char *dst_filename, int dst_rate)
goto end;
}
/* allocate source and destination samples buffers */
src_nb_channels = av_get_channel_layout_nb_channels(src_ch_layout);
/* compute the number of converted samples: buffering is avoided
* ensuring that the output buffer will contain at least all the
* converted input samples */
@ -120,21 +169,9 @@ int resampling(const char *src_filename, const char *dst_filename, int dst_rate)
goto end;
}
avformat_alloc_output_context2(&oformat_ctx, nullptr, nullptr, dst_filename);
av_dump_format(oformat_ctx, 0, dst_filename, 1);
if (!(oformat_ctx->oformat->flags & AVFMT_NOFILE)) {
ret = avio_open(&oformat_ctx->pb, dst_filename, AVIO_FLAG_WRITE);
if (ret < 0) {
ALOGE("Could not open output file %s\n", dst_filename);
return ret;
}
}
/* init muxer, write output file header */
ret = avformat_write_header(oformat_ctx, nullptr);
if (ret < 0) {
ALOGE("Error occurred when opening output file\n");
return ret;
}
init_audio_decoder(iformat_ctx, icodec_ctx);
init_audio_encoder(oformat_ctx, ocodec_ctx);
init_audio_muxer(oformat_ctx, dst_filename);
while (av_read_frame(iformat_ctx, &packet) >= 0) {
/* compute destination number of samples */
@ -149,7 +186,7 @@ int resampling(const char *src_filename, const char *dst_filename, int dst_rate)
max_dst_nb_samples = dst_nb_samples;
}
ret = avcodec_decode_audio4(iformat_ctx, frame, &got_frame_ptr, packet);
ret = avcodec_decode_audio4(icodec_ctx, frame, &got_frame_ptr, &packet);
if (ret < 0) {
ALOGE("decode audio error:%d\n", ret);
continue;
@ -168,17 +205,24 @@ int resampling(const char *src_filename, const char *dst_filename, int dst_rate)
goto end;
}
ret = avcodec_encode_audio2(ocodec_ctx, opacket, frame, &got_packet_ptr);
if (ret < 0) {
ALOGE("encode audio error=%d\n", ret);
continue;
}
AVStream *in_stream = iformat_ctx->streams[0];
AVStream *out_stream = oformat_ctx->streams[0];
pkt->pts = av_rescale_q_rnd(packet.pts, in_stream->time_base, out_stream->time_base,
opacket->pts = av_rescale_q_rnd(packet.pts, in_stream->time_base, out_stream->time_base,
static_cast<AVRounding>(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));
pkt->dts = av_rescale_q_rnd(packet.dts, in_stream->time_base, out_stream->time_base,
opacket->dts = av_rescale_q_rnd(packet.dts, in_stream->time_base, out_stream->time_base,
static_cast<AVRounding>(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));
pkt->duration = av_rescale_q(packet.duration, in_stream->time_base, out_stream->time_base);
pkt->pos = -1;
opacket->duration = av_rescale_q(packet.duration, in_stream->time_base, out_stream->time_base);
opacket->pos = -1;
av_interleaved_write_frame(oformat_ctx, pkt);
av_interleaved_write_frame(oformat_ctx, opacket);
av_packet_unref(opacket);
av_packet_unref(&packet);
}
@ -190,6 +234,9 @@ int resampling(const char *src_filename, const char *dst_filename, int dst_rate)
end:
av_packet_free(&opacket);
av_frame_free(&frame);
if (dst_data)
av_freep(&dst_data[0]);
av_freep(&dst_data);

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