[Libav-user] 4k video decoding planner data

[Don Moir]

 >y_1strow += Width;
 >y_2ndrow += Width;

Check this to see if it is your problem.

Appears you should be using the pitch for this and not the width. 
Normally width is width of video and pitch is the number of bytes per 
line and can be greater than width.

On 7/27/2016 11:05 PM, Ankush Wadke wrote:
> Thanks for the reply Harry.
> And yes it has something to do with the offset of U and V planes but 
> it works perfectly fine for a FHD stream i.e. 1920x1080 but dosent 
> seem to for a 3840x2160 stream. Does planer data require alignment to 
> be considered?
>
> On Wed, Jul 27, 2016 at 7:51 PM, Harry <Harry at gps-laptimer.de 
> <mailto:Harry at gps-laptimer.de>> wrote:
>
>     Green borders are a wrong offset / starting address for the UV planes.
>
>     Harry
>
>     Sent from my smartphone
>
>     On 27 Jul 2016, at 11:47, Ankush Wadke <wadkes93 at gmail.com
>     <mailto:wadkes93 at gmail.com>> wrote:
>
>>     Hi everybody,
>>         I am stuck with a problem to which I am not able to figure
>>     out what exactly is wrong.
>>         I am decoding a 4k video which gives me a YUV420P output
>>     frame. In order to convert it to UYVY I wrote a piece of code.
>>     which works fine for first frame, then second frame has a small
>>     green line and the third frame has the colors totally displaced.
>>     I am getting the correct frames sometimes but i am not able to
>>     figure out what is wrong with the other frames.
>>         It would be really helpful if someone would point me to
>>     something tat would help.
>>
>>     hers the code i am using for conversion,
>>
>>     void Convert_yuv420_to_yuv422(const AVFrame &videoBuffer, uint8_t
>>     * opBuffer, const int const &Width,  const int const &Height)
>>     {
>>     uint8_t  *buffer_uyvy_1strow = opBuffer,
>>                         *buffer_uyvy_2ndrow = opBuffer+(2*Width);
>>
>>     uint8_t*y_1strow = videoBuffer.data[0],
>>     *y_2ndrow = videoBuffer.data[0]+Width;
>>
>>     uint8_t * u_ptr = videoBuffer.data[1];
>>     uint8_t * v_ptr = videoBuffer.data[2];
>>
>>     for (unsigned int i_conv_ht =0; i_conv_ht<Height;i_conv_ht+=2) {
>>     for (unsigned int i_conv_wt =0; i_conv_wt<Width;i_conv_wt+=2) {
>>     *buffer_uyvy_1strow++ = *u_ptr;
>>     *buffer_uyvy_1strow++ = *y_1strow++;
>>     *buffer_uyvy_1strow++ = *v_ptr;
>>     *buffer_uyvy_1strow++ = *y_1strow++;
>>
>>     *buffer_uyvy_2ndrow++ = *u_ptr;
>>     *buffer_uyvy_2ndrow++ = *y_2ndrow++;
>>     *buffer_uyvy_2ndrow++ = *v_ptr;
>>     *buffer_uyvy_2ndrow++ = *y_2ndrow++;
>>
>>     ++u_ptr;
>>     ++v_ptr;
>>     }
>>     y_1strow += Width;
>>     y_2ndrow += Width;
>>
>>     buffer_uyvy_1strow += FFALIGN((2*Width),1);
>>     buffer_uyvy_2ndrow += FFALIGN((2*Width),1);
>>     }
>>     }
>>
>>     Regards,
>>     Ankush
>>
>>      *
>>
>>      *
>>
>>
>>     _______________________________________________
>>     Libav-user mailing list
>>     Libav-user at ffmpeg.org <mailto:Libav-user at ffmpeg.org>
>>     http://ffmpeg.org/mailman/listinfo/libav-user
>
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>
>
>
> -- 
> *Ankush Wadke
>
> *
> Mob: 9673898604
> Email: wadkes93 at gmail.com <mailto:wadkes93 at gmail.com>
>
>  *
>
>   * in.linkedin.com/pub/ankush-wadke/36/868/981/
>     <http://in.linkedin.com/pub/ankush-wadke/36/868/981/>
>
>
>
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