[FFmpeg-devel] [PATCH 3/4 v2] avcodec/libx265: export encoded frame stats

[James Almer]

On 12/30/2019 8:06 PM, Derek Buitenhuis wrote:
> On 30/12/2019 19:20, James Almer wrote:
>> +    ff_side_data_set_encoder_stats(pkt, x265pic_out.frameData.qp * FF_QP2LAMBDA, NULL, 0, pict_type);
> 
> Does multiplying by FF_QP2LAMBDA even make sense here? That contsant
> is for H.263's QP scale, not HEVC's.

Pretty much every call to ff_side_data_set_encoder_stats() in lavc does
it, including libx264, so i figure it's expected.

For example, encoding with -qp 28 i get

> out=  0 st=  0 frame=     1 q= 25.0 f_size=   2726 s_size=        3kB time= 0.010 br=   523.4kbits/s avg_br=  2180.8kbits/s type= I
> out=  0 st=  0 frame=     2 q= 28.0 f_size=    181 s_size=        3kB time= 0.010 br=    34.8kbits/s avg_br=  2325.6kbits/s type= P
> out=  0 st=  0 frame=     3 q= 29.0 f_size=     61 s_size=        3kB time= 0.010 br=    11.7kbits/s avg_br=  2374.4kbits/s type= B
> out=  0 st=  0 frame=     4 q= 30.0 f_size=     27 s_size=        3kB time= 0.042 br=     5.2kbits/s avg_br=   573.9kbits/s type= B

with it, but

> out=  0 st=  0 frame=     1 q= 0.2 f_size=   2726 s_size=        3kB time= 0.010 br=   523.4kbits/s avg_br=  2180.8kbits/s type= I
> out=  0 st=  0 frame=     2 q= 0.2 f_size=    181 s_size=        3kB time= 0.010 br=    34.8kbits/s avg_br=  2325.6kbits/s type= P
> out=  0 st=  0 frame=     3 q= 0.2 f_size=     61 s_size=        3kB time= 0.010 br=    11.7kbits/s avg_br=  2374.4kbits/s type= B
> out=  0 st=  0 frame=     4 q= 0.3 f_size=     27 s_size=        3kB time= 0.042 br=     5.2kbits/s avg_br=   573.9kbits/s type= B

without it.