[Ffmpeg-devel] Re: Re: Odd AVFrame.linesize Values when Decoding MPEG2

[QuickTime]

Dear:

> Rich Felker wrote:
>
> > If you enable edge emulation (which also makes decoding faster) then
> > linesize will be equal to width as long as width is a multiple of 16,
> > but you should not rely on this to be the case.
>
> CODEC_FLAG_EMU_EDGE solved the problem. It's not something I would have
> found anywhere. Thanks for the tip.
>
> Paul
>
Well, Never rely on the CODEC_FLAG_EMU_EDGE Flag, It's will put an
overwhelming impact on the whole performance!!!
linesize is only suit for ME/MC with some padding areas
You should use AVCodecContext->width and AVCodecContext->height instead.
e.g:
int yuv2file_filter(AVPicture *pic,int yuv_index,int width,int height)
{	
	char yuv_file_index_string[32];
	char yuv_file_name[64]="e:\\temp\\yuv_";
	FILE *fp;
	
	if(!pic)
		return -1;

	sprintf(yuv_file_index_string,"%d.yuv",yuv_index);
	strcat(yuv_file_name,yuv_file_index_string);
	fp=fopen(yuv_file_name,"wb");
	if(fp)
	{
		int i,k,shift;
		char *yuv_ptr;

		for(k=0;k<3;k++)
		{
			shift = (k==0 ?0:1);
			yuv_ptr=pic->data[k];
			for(i=0; i<(height>>shift);i++)
			{
				fwrite(yuv_ptr,(width>>shift),1,fp);
				yuv_ptr+=pic->linesize[k];
			}
		}
		fclose(fp);
	}

	return 0;
}