[FFmpeg-user] Transcoding for the Roku with recent ffmpeg

[Yan Seiner]

Carl Eugen Hoyos wrote:
> Yan Seiner <yan <at> seiner.com> writes:
>
>   
>> Well, my latest effort is pretty close:
>>
>> ffmpeg 1.0
>>
>> < Bits/(Pixel*Frame)       : 0.152
>> < Stream size              : 1.57 GiB (89%)
>> < Writing library          : x264 core 129 r2230 1cffe9f
>> crf=19.0
>>     
>
>   
>> ffmpeg 0.8
>>
>>     
>>> Bits/(Pixel*Frame)       : 0.163
>>> Stream size              : 937 MiB (88%)
>>> Writing library          : x264 core 114
>>>       
>> bitrate=1200
>>     
>
> These are still *completely* different files.
>
> Did you already test 0.8 with a newer x264 or current FFmpeg 
> with older x264?
>   
ffmpeg 1.0 with older x264:

Writing library                          : x264 core 118
Encoding settings                        : cabac=0 / ref=2 / 
deblock=1:0:0 / analyse=0x1:0x111 / me=hex / subme=6 / psy=1 / 
psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=0 / 
8x8dct=0 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / 
threads=3 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / 
bluray_compat=0 / constrained_intra=0 / bframes=0 / weightp=0 / 
keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / 
rc_lookahead=40 / rc=crf / mbtree=1 / crf=22.0 / qcomp=0.60 / qpmin=10 / 
qpmax=51 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00

Same result; plays about 30 seconds then rebuffers.

The ones that play are all variable bit rate; the ones that refuse to 
play are constant bit rate.  How do I set vbr?  (I know this is probably 
a dumb question but I've never had to set it explicitly.)

--Yan