Hi,
I am facing issue while encoding live capture video data.
i want to encode raw video data captured from web cam into wmv2 codec.
i am able to encode the video frames & write them in a file , but @ decoding
side it shows lot of mess.
pls have a look at my code below
actually i have some queries , pls resolve them.
1 what should be container format for this output file.
2 As sson as i captured first frame i start writing them to file , i am not
writing any header info , pls let me know how to get this header.
when i tried to decode this file it says
picture size invalid (0x0)
[rawvideo @ 0x3edb30]Could not find codec parameters
(Video: rawvideo, yuv420p)
Straem info can't be retrieve
Regards
Ajay
==============================================================================================
void My_Video_Encode()
{
const char *ofilename = "D:\\Ajay\\video\\myenc.yuv";
AVOutputFormat *fmt = NULL;
AVFormatContext *pInFormatCtx = NULL;
AVCodec *codec = NULL;
int i = 0;
#if WIN_CAP
FILE *f;
AVFrame *Rframe = NULL;
AVPacket packet ;
AVCodecContext *pCodecCtx = NULL;
AVFormatParameters formatParams;
AVInputFormat *pInfmt = NULL;
uint8_t *outbuf = NULL;
int size, out_size ,outbuf_size , ret ;
memset(&formatParams, 0, sizeof(AVFormatParameters));
formatParams.time_base.num = 1;
formatParams.time_base.den = 25;
#endif
f = fopen(ofilename, "wb");
if (!f)
{
fprintf(stderr, "could not open %s\n", ofilename);
exit(1);
}
av_register_all();
/* allocate the output media context */
#if WIN_CAP
avdevice_register_all();
pInfmt = av_find_input_format("vfwcap");
if( !pInfmt )
{
fprintf(stderr,"Unknown input format:mjpeg\n");
return -1;
}
if (av_open_input_file(&pInFormatCtx, "0", pInfmt, 0, &formatParams) != 0)
printf( "Could not open input file for windows \n");
#endif
if(av_find_stream_info(pInFormatCtx) <0)
printf("Stream info can't be retrieve \n" );
dump_format( pInFormatCtx , 0 ,"0" ,0 ) ;
fmt = guess_format("rawvideo", "vfwcap", NULL);
pInFormatCtx->oformat = fmt;
/* ptr to codec ctx for video stream */
pCodecCtx = pInFormatCtx->streams[0]->codec ;
/* put sample parameters */
pCodecCtx->bit_rate = 400000;
/* resolution must be a multiple of two */
pCodecCtx->max_b_frames=0;
pCodecCtx->codec_id = CODEC_ID_WMV2 ;
codec = avcodec_find_encoder(CODEC_ID_WMV2);
if (!codec)
{
fprintf(stderr, "codec not found\n");
exit(1);
}
if (avcodec_open(pCodecCtx, codec) < 0)
{
fprintf(stderr, "could not open codec\n");
exit(1);
}
Rframe = avcodec_alloc_frame();
if (!Rframe)
return NULL;
outbuf_size = 100000;
outbuf = malloc(outbuf_size);
size = pCodecCtx->width * pCodecCtx->height;
while (av_read_frame (pInFormatCtx , &packet ) >= 0)
{
Rframe->data[0] = packet.data;
Rframe->data[1] = Rframe->data[0] + size;
Rframe->data[2] = Rframe->data[1] + size / 4;
Rframe->linesize[0] = pCodecCtx->width;
Rframe->linesize[1] = pCodecCtx->width / 2;
Rframe->linesize[2] = pCodecCtx->width / 2;
out_size = avcodec_encode_video(pCodecCtx, outbuf, outbuf_size, Rframe);
printf("encoding frame %3d (size=%5d)\n", i, out_size);
fwrite(outbuf, 1, out_size, f);
if (i++ > 100)
break;
}
fclose(f);
}
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