> On 19 Jan 2006, at 22:42, Endaf Jones wrote: > > >> Modified: > >> > >> trunk/mythtv/libs/libmythtv/videobuffers.cpp > >> > >> Log: > >> > >> Fixes #1053. > >> > >> In this case an MPEG-4 recording is using a frame height which is not > >> a multiple of 16. ffmpeg isn't doing any validation on the dimensions > >> so it ends up writing outside the buffer. This just pads allocated > >> buffers up to multiples of 16, so that this type of error doesn't > >> cause > >> a segfault with any of the codecs we support. MythTV does prevent you > >> from setting an invalid dimension when you record to a MPEG-4 NUV, so > >> AFAIK this is more of a legacy issue. > > > > Question.. > > > > What about transcoding MPEG2 into MPEG4 after a recording and you have > > "Resize Video while transcoding" AND the newly developed "Preserve > > Aspect Ratio of Video when resizing" option? The height is auto > > calculated in that case. > > > > Is this situation the same as the above commit? > > > > I say this because I have a PBS HDTV program 1920x1080i that I > > transcode into a 544 wide MPEG4 so I can view it on my SDTV. The > > height works out to be 302 or so pixels (to keep the aspect correct). > > When I play that newly encoded file, I have a strange color cast on > > the top 1/6th of the picture. > > > > Same problem or different? > > > > -- > > # Endaf
On 1/19/06, Dave Just <[EMAIL PROTECTED]> wrote: > Yes! This is just the situation I had. I have my low quality > transcode settings to rescale from usual capture resolution of > 720x576 down to 480x384. Both multiples of 16. But then I also > added the "Preserve aspect option" when it appeared. The result was > that some of my captures which are at 4:3 instead of 16:9 got scaled > to a larger height, 392, not divisible by 16... and yes, the > transcoded files have fuzzy green borders in the top 1/6th or so. > > I'm disabling the "preserve aspect ratio" for now again. Maybe that > option needs tuning to enforce the standards. (BTW, wouldn't it be > better to scale the width according to the desired height anyway? I > think it's more useful to specify vertical resolution to match output > device) > Glad to see I wasn't the only one with a strange color overlay at the top. I also wondered if there is value in fixing the aspect ratio to the height instead of the width (or have the option between the two). -- # Endaf _______________________________________________ mythtv-dev mailing list [email protected] http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-dev
