[x264-devel] output at crf 20 larger than source??

[sean darcy]

On Sun, Sep 11, 2011 at 12:40 PM, Igor Mozolevsky <igor at hybrid-lab.co.uk> wrote:
> On 11 September 2011 17:31, sean darcy <seandarcy2 at gmail.com> wrote:
>
>>>>    Stream #0.0[0x810]: Video: mpeg2video (Main) ([2][0][0][0] /
>>>> 0x0002), yuv420p, 1440x1080 [SAR 4:3 DAR 16:9], 25000 kb/s, 29.97 fps,
>>>> 29.97 tbr, 90k tbn, 59.94 tbc
>
>> Where did you get the 560,000 kb/s? Or is this 20+ ratio "Just Known"?
>
> 1440*1080 * 1.5 * 30000/1001 * 8 ~= 560 Mbps
>
> frame size * yuv coding (full size Y plane + 1/4 size U + 1/4 size V
> plane) * fps * bits/sample
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Got it. Thanks.

BTW, does anyone have another way of converting this sort of
mpeg2video to y4m input to x264?

ffmpeg chokes without output:

 ffmpeg -i Act1a-2011.08.20_20-27-08.m2t -an -vcodec libx264  -preset
veryslow -tune film -b 2500 -r 60000/1001 -threads 0 output2.m4v
..........
[mpegts @ 0xa0f5e0] Continuity Check Failed
[mpegts @ 0xa0f5e0] PES packet size mismatch
[mpegts @ 0xa0f5e0] parser not found for codec none, packets or times
may be invalid.
[mpegts @ 0xa0f5e0] PES packet size mismatch
    Last message repeated 1 times
[mpegts @ 0xa0f5e0] parser not found for codec none, packets or times
may be invalid.
[mpegts @ 0xa0f5e0] PES packet size mismatch
    Last message repeated 23 times

Does libav do any better??

mplayer seems to like only crf:

 mplayer -nosound -benchmark -vo yuv4mpeg:file=>(x264 --demuxer y4m
--bitrate 3000  --preset veryslow --tune film --output act1a-3000.264
) Act1a-2011.08.20_20-27-08.m2t
................
Movie-Aspect is 1.78:1 - prescaling to correct movie aspect.
VO: [yuv4mpeg] 1440x1080 => 1920x1080 Planar YV12


MPlayer interrupted by signal 13 in module: decode_video


MPlayer interrupted by signal 13 in module: flip_page

sean