#include <stdlib.h>
#include <string.h>
+#include "libavutil/channel_layout.h"
#include "libavutil/frame.h"
#include "libavutil/mem.h"
#define AUDIO_INBUF_SIZE 20480
#define AUDIO_REFILL_THRESH 4096
+static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame,
+ FILE *outfile)
+{
+ int16_t *interleave_buf;
+ int ret, data_size, i;
+
+ /* send the packet with the compressed data to the decoder */
+ ret = avcodec_send_packet(dec_ctx, pkt);
+ if (ret < 0) {
+ fprintf(stderr, "Error submitting the packet to the decoder\n");
+ exit(1);
+ }
+
+ /* read all the output frames (in general there may be any number of them */
+ while (ret >= 0) {
+ ret = avcodec_receive_frame(dec_ctx, frame);
+ if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
+ return;
+ else if (ret < 0) {
+ fprintf(stderr, "Error during decoding\n");
+ exit(1);
+ }
+
+ /* the stream parameters may change at any time, check that they are
+ * what we expect */
+ if (av_get_channel_layout_nb_channels(frame->channel_layout) != 2 ||
+ frame->format != AV_SAMPLE_FMT_S16P) {
+ fprintf(stderr, "Unsupported frame parameters\n");
+ exit(1);
+ }
+
+ /* The decoded data is signed 16-bit planar -- each channel in its own
+ * buffer. We interleave the two channels manually here, but using
+ * libavresample is recommended instead. */
+ data_size = sizeof(*interleave_buf) * 2 * frame->nb_samples;
+ interleave_buf = av_malloc(data_size);
+ if (!interleave_buf)
+ exit(1);
+
+ for (i = 0; i < frame->nb_samples; i++) {
+ interleave_buf[2 * i] = ((int16_t*)frame->data[0])[i];
+ interleave_buf[2 * i + 1] = ((int16_t*)frame->data[1])[i];
+ }
+ fwrite(interleave_buf, 1, data_size, outfile);
+ av_freep(&interleave_buf);
+ }
+}
+
int main(int argc, char **argv)
{
const char *outfilename, *filename;
const AVCodec *codec;
AVCodecContext *c= NULL;
- int len;
+ AVCodecParserContext *parser = NULL;
+ int len, ret;
FILE *f, *outfile;
uint8_t inbuf[AUDIO_INBUF_SIZE + AV_INPUT_BUFFER_PADDING_SIZE];
- AVPacket avpkt;
+ uint8_t *data;
+ size_t data_size;
+ AVPacket *pkt;
AVFrame *decoded_frame = NULL;
if (argc <= 2) {
/* register all the codecs */
avcodec_register_all();
- av_init_packet(&avpkt);
+ pkt = av_packet_alloc();
/* find the MPEG audio decoder */
codec = avcodec_find_decoder(AV_CODEC_ID_MP2);
exit(1);
}
+ parser = av_parser_init(codec->id);
+ if (!parser) {
+ fprintf(stderr, "parser not found\n");
+ exit(1);
+ }
+
c = avcodec_alloc_context3(codec);
/* open it */
}
/* decode until eof */
- avpkt.data = inbuf;
- avpkt.size = fread(inbuf, 1, AUDIO_INBUF_SIZE, f);
-
- while (avpkt.size > 0) {
- int got_frame = 0;
+ data = inbuf;
+ data_size = fread(inbuf, 1, AUDIO_INBUF_SIZE, f);
+ while (data_size > 0) {
if (!decoded_frame) {
if (!(decoded_frame = av_frame_alloc())) {
fprintf(stderr, "out of memory\n");
}
}
- len = avcodec_decode_audio4(c, decoded_frame, &got_frame, &avpkt);
- if (len < 0) {
- fprintf(stderr, "Error while decoding\n");
+ ret = av_parser_parse2(parser, c, &pkt->data, &pkt->size,
+ data, data_size,
+ AV_NOPTS_VALUE, AV_NOPTS_VALUE, 0);
+ if (ret < 0) {
+ fprintf(stderr, "Error while parsing\n");
exit(1);
}
- if (got_frame) {
- /* if a frame has been decoded, output it */
- int data_size = av_samples_get_buffer_size(NULL, c->channels,
- decoded_frame->nb_samples,
- c->sample_fmt, 1);
- fwrite(decoded_frame->data[0], 1, data_size, outfile);
- }
- avpkt.size -= len;
- avpkt.data += len;
- if (avpkt.size < AUDIO_REFILL_THRESH) {
- /* Refill the input buffer, to avoid trying to decode
- * incomplete frames. Instead of this, one could also use
- * a parser, or use a proper container format through
- * libavformat. */
- memmove(inbuf, avpkt.data, avpkt.size);
- avpkt.data = inbuf;
- len = fread(avpkt.data + avpkt.size, 1,
- AUDIO_INBUF_SIZE - avpkt.size, f);
+ data += ret;
+ data_size -= ret;
+
+ if (pkt->size)
+ decode(c, pkt, decoded_frame, outfile);
+
+ if (data_size < AUDIO_REFILL_THRESH) {
+ memmove(inbuf, data, data_size);
+ data = inbuf;
+ len = fread(data + data_size, 1,
+ AUDIO_INBUF_SIZE - data_size, f);
if (len > 0)
- avpkt.size += len;
+ data_size += len;
}
}
+ /* flush the decoder */
+ pkt->data = NULL;
+ pkt->size = 0;
+ decode(c, pkt, decoded_frame, outfile);
+
fclose(outfile);
fclose(f);
avcodec_free_context(&c);
+ av_parser_close(parser);
av_frame_free(&decoded_frame);
+ av_packet_free(&pkt);
return 0;
}