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examples/decoding_encoding: add and use the decode_write_frame function

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Allow to factorize code in video_decode_example(), simplify.
This commit is contained in:
Stefano Sabatini 2012-10-20 11:26:05 +02:00
parent 4a227a706d
commit 33c4535db7
1 changed files with 32 additions and 33 deletions
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65
doc/examples/decoding_encoding.c
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@ -487,15 +487,42 @@ static void pgm_save(unsigned char *buf, int wrap, int xsize, int ysize,
fclose(f); fclose(f);
} }
static int decode_write_frame(const char *outfilename, AVCodecContext *avctx,
AVFrame *frame, int *frame_count, AVPacket *pkt, int last)
{
int len, got_frame;
char buf[1024];
len = avcodec_decode_video2(avctx, frame, &got_frame, pkt);
if (len < 0) {
fprintf(stderr, "Error while decoding frame %d\n", *frame_count);
return len;
}
if (got_frame) {
printf("Saving %sframe %3d\n", last ? "last " : "", *frame_count);
fflush(stdout);
/* the picture is allocated by the decoder, no need to free it */
snprintf(buf, sizeof(buf), outfilename, *frame_count);
pgm_save(frame->data[0], frame->linesize[0],
avctx->width, avctx->height, buf);
(*frame_count)++;
}
if (pkt->data) {
pkt->size -= len;
pkt->data += len;
}
return 0;
}
static void video_decode_example(const char *outfilename, const char *filename) static void video_decode_example(const char *outfilename, const char *filename)
{ {
AVCodec *codec; AVCodec *codec;
AVCodecContext *c= NULL; AVCodecContext *c= NULL;
int frame_count, got_frame, len; int frame_count;
FILE *f; FILE *f;
AVFrame *frame; AVFrame *frame;
uint8_t inbuf[INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE]; uint8_t inbuf[INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE];
char buf[1024];
AVPacket avpkt; AVPacket avpkt;
av_init_packet(&avpkt); av_init_packet(&avpkt);
@ -565,26 +592,9 @@ static void video_decode_example(const char *outfilename, const char *filename)
/* here, we use a stream based decoder (mpeg1video), so we /* here, we use a stream based decoder (mpeg1video), so we
feed decoder and see if it could decode a frame */ feed decoder and see if it could decode a frame */
avpkt.data = inbuf; avpkt.data = inbuf;
while (avpkt.size > 0) { while (avpkt.size > 0)
len = avcodec_decode_video2(c, frame, &got_frame, &avpkt); if (decode_write_frame(outfilename, c, frame, &frame_count, &avpkt, 0) < 0)
if (len < 0) {
fprintf(stderr, "Error while decoding frame %d\n", frame_count);
exit(1); exit(1);
}
if (got_frame) {
printf("Saving frame %3d\n", frame_count);
fflush(stdout);
/* the picture is allocated by the decoder. no need to
free it */
snprintf(buf, sizeof(buf), outfilename, frame_count);
pgm_save(frame->data[0], frame->linesize[0],
c->width, c->height, buf);
frame_count++;
}
avpkt.size -= len;
avpkt.data += len;
}
} }
/* some codecs, such as MPEG, transmit the I and P frame with a /* some codecs, such as MPEG, transmit the I and P frame with a
@ -592,18 +602,7 @@ static void video_decode_example(const char *outfilename, const char *filename)
chance to get the last frame of the video */ chance to get the last frame of the video */
avpkt.data = NULL; avpkt.data = NULL;
avpkt.size = 0; avpkt.size = 0;
len = avcodec_decode_video2(c, frame, &got_frame, &avpkt); decode_write_frame(outfilename, c, frame, &frame_count, &avpkt, 1);
if (got_frame) {
printf("Saving last frame %3d\n", frame_count);
fflush(stdout);
/* the picture is allocated by the decoder. no need to
free it */
snprintf(buf, sizeof(buf), outfilename, frame_count);
pgm_save(frame->data[0], frame->linesize[0],
c->width, c->height, buf);
frame_count++;
}
fclose(f); fclose(f);