Hello folks, I'm new to the list, and just joined to make this request. I was writing a python script to convert MKV video files to iPad/iPod/PS3/360 compatible MP4 files and discovered kaa.metadata. It's much nicer than parsing the output of mkvinfo - thanks!
The goal of my script is to avoid re-encoding the video where possible. One of the things I check is the H.264 Profile and Level to determine compatibility with the target device (http://en.wikipedia.org/wiki/H.264/MPEG-4_AVC#Profiles). For example, the iPad supports Main Profile Level 3.1 (http://www.apple.com/ipad/specs/), whereas the PS3 supports Main Profile Level 4.1 (http://en.wikipedia.org/wiki/H.264/MPEG-4_AVC_products_and_implementations#Decoding). If the Profile/Level in the source file is too high, I need to re-encode the video. Since kaa.metadata.parse() does not provide the codec private data for video tracks inside MKV containers, I've modified mkv.py on my local machine to expose it (see diff below). This seems like a simple way to allow clients of the API to access this data without adding support for parsing the private data directly (which is different for each video codec). I'd also suggest that the variable name be changed from "codec_private_id" to "codec_private", but I wanted to keep my changes minimal. Hopefully you'll find this useful and incorporate it into kaa.metadata, so my script can be run by others someday. Thanks, Mike. P.S. I made my change on my Ubuntu box, using the version of kaa.metadata provided in the standard repository (0.7.7-2). The version in SVN looks similar for this section, but I didn't try to apply it there. --- mkv.py.orig 2010-08-30 17:41:41.300467825 -0400 +++ mkv.py 2010-09-14 17:15:32.414917557 -0400 @@ -449,10 +449,10 @@ def process_video_track(self, elements): track = core.VideoStream() - codec_private_id = '' # Defaults track.codec = u'Unknown' track.fps = 0 + track.codec_private_id = '' for elem in elements: elem_id = elem.get_id() @@ -485,7 +485,7 @@ track.aspect = float(d_width) / d_height elif elem_id == MATROSKA_CODEC_PRIVATE_ID: - codec_private_id = elem.get_data() + track.codec_private_id = elem.get_data() else: self.process_track_common(elem, track) @@ -496,8 +496,8 @@ track.codec = FOURCCMap[track.codec] elif '/' in track.codec and track.codec.split('/')[0] + '/' in FOURCCMap: track.codec = FOURCCMap[track.codec.split('/')[0] + '/'] - elif track.codec.endswith('FOURCC') and len(codec_private_id) == 40: - track.codec = codec_private_id[16:20] + elif track.codec.endswith('FOURCC') and len(track.codec_private_id) == 40: + track.codec = track.codec_private_id[16:20] elif track.codec.startswith('V_REAL/'): track.codec = track.codec[7:] elif track.codec.startswith('V_'): ------------------------------------------------------------------------------ Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev _______________________________________________ Freevo-devel mailing list Freevo-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freevo-devel
