February 2010 - ffmpeg-devel - lists.ffmpeg.org

[PATCH] Add writing of vorbis comments to flac files
by james.darnley＠gmail.com 20 Mar '10

20 Mar '10

Hello, I have attached a patch which adds the creation of vorbis comments from AVMetadata and the writing of this as a METADATA_BLOCK_VORBIS_COMMENT in a flac file. Could someone please double check libavformat/makefile and the #includes on the files to eliminate any redundant options or to add any I have missed. I do have a question or two. Is it possible to determine the length of the audio from the AVFormatContext struct? I tried a couple of "duration" values but they always seemed to be 0. If that is not possible, is there a value in AVFormatContext which could be interpreted as a header padding value, a value which might request N bytes of padding? I ask because there is also the possibility of writing a METADATA_BLOCK_PADDING to allow extra metadata or possibly a seek table to be added later without the need to rewrite the whole file. Thanks for any comments.

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[PATCH] Fix SDP demuxer dependencies
by martin＠martin.st 15 Mar '10

15 Mar '10

Hi, The SDP demuxer includes rtp_asf.o and rdt.o, which depend on the asf and rm demuxers. If compiling with e.g. these options, --disable-demuxers --disable-muxers --disable-protocols --disable-encoders --disable-decoders --disable-parsers --disable-bsfs --enable-protocol=udp --enable-demuxer=mpegts --enable-protocol=rtp --enable-demuxer=sdp one gets a linker failure. The attached patch fixes this issue. // Martin

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[PATCH] Export large crop values via AVCodecContext
by lessen42＠gmail.com 13 Mar '10

13 Mar '10

Hi, As far as I can tell, it's impractical to crop large values internally, since buffers returned from decode_frame must have the same dimensions as AVCodecContext, which also must be the coded dimensions (or up to 15 less) in order for get_buffer to allocate buffers of the needed size. Thus, the only solution I see is to export these values and leave it to individual applications that care about such offsets to deal with it themselves.

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[PATCH] Move error codes definitions from lavc to lavu
by stefano.sabatini-lala＠poste.it 13 Mar '10

13 Mar '10

Hi, as in subject, this is required if we want for example move the error handling code to lavu, as it uses it. Also reduces the clutter in avcodec.h. Regards. -- FFmpeg = Free & Funny Mean Portable Elaborated Generator

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[PATCH] swscale: Check whether slice height is multiple of chroma subsample.
by ramiro.polla＠gmail.com 13 Mar '10

13 Mar '10

Hi, Check whether slice height is multiple of chroma subsample. Currently if we take a 410p image and rescale with sliceH = 1, the output is black&white. I did this using the test tool at [1] (renamed to swscale-test2) and the command: ./swscale-test2 -i input.bmp -sws_flags bicubic -pix_fmt yuv410p -s 320x320 -scale -sliceH 1 -pix_fmt bgr24 -scale -o output.bmp I found it weird that this code in utils.c expects the slices to start on subsample boundaries (by shifting nextSlice back and forth), but sws_scale() doesn't: // calculate buffer sizes so that they won't run out while handling these damn slices c->vLumBufSize= c->vLumFilterSize; c->vChrBufSize= c->vChrFilterSize; for (i=0; i<dstH; i++) { int chrI= i*c->chrDstH / dstH; int nextSlice= FFMAX(c->vLumFilterPos[i ] + c->vLumFilterSize - 1, ((c->vChrFilterPos[chrI] + c->vChrFilterSize - 1)<<c->chrSrcVSubSample)); nextSlice>>= c->chrSrcVSubSample; nextSlice<<= c->chrSrcVSubSample; if (c->vLumFilterPos[i ] + c->vLumBufSize < nextSlice) c->vLumBufSize= nextSlice - c->vLumFilterPos[i]; if (c->vChrFilterPos[chrI] + c->vChrBufSize < (nextSlice>>c->chrSrcVSubSample)) c->vChrBufSize= (nextSlice>>c->chrSrcVSubSample) - c->vChrFilterPos[chrI]; } Ramiro Polla [1] http://article.gmane.org/gmane.comp.video.ffmpeg.devel/102702

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Missing dependencies.
by ramiro.polla＠gmail.com 10 Mar '10

10 Mar '10

Hi, I tested configuring and building FFmpeg with only one component selected at a time, with a script that did something like: ../svn/configure --disable-demuxers --disable-muxers --disable-decoders --disable-encoders --disable-parsers --disable-indevs --disable-outdevs --disable-bsfs --cc="ccache gcc" --disable-doc --disable-ffplay --disable-ffserver --enable-$component=$item for all decoders, encoders, demuxers, muxers, and parsers. These are the ones that fail at make: decoders: als binkaudio_rdft twinvq wmv1 encoders: msmpeg4v1 msmpeg4v2 msmpeg4v3 snow svq1 gif wmv2 demuxers: aea caf wv iff muxers (all ok) parsers: mpeg4video h264 vc1 Ramiro Polla

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[PATCH] Kega Game Video (KGV1) decoder
by daniel＠drv.nu 09 Mar '10

09 Mar '10

Hi, This is a video capture codec used by the Kega emulator. See http://wiki.multimedia.cx/index.php?title=Kega_Video for more information. Thanks, -- Daniel Verkamp

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[PATCH] asf chapter support
by pan＠nt.tu-darmstadt.de 08 Mar '10

08 Mar '10

ASF supports "markers" which are a name and a time stamp, attached patch uses them to crate lavf chapters. As the markers only provide a start time, I use the start time of the next marker or the total duration of the file as the end time for the chapter. Regards, Vladimir

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[PATCH] improvement on r21598 ("fix stream copy")
by wmglo＠dent.med.uni-muenchen.de 08 Mar '10

08 Mar '10

Hi, When using ffmpeg -t, after r21598: + /* finish if recording time exhausted */ + if (pkt.pts * av_q2d(ist->st->time_base) >= (recording_time / 1000000.0)) + goto discard_packet; the test near line ffmpeg.c:2254: /* finish if recording time exhausted */ if (opts_min >= (recording_time / 1000000.0)) break; doesn't trigger anymore, because no packets with opts_min larger than recording time are ever output (they are just discarded -- like they should be). So, everything still works correctly, but all input files are needlessly read until EOF, and there are also timestamp discontinuity warnings output every ten seconds. How about the appended patch? Regards, Wolfram.

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[PATCH] Add support to input device to ffprobe
by stefano.sabatini-lala＠poste.it 07 Mar '10

07 Mar '10

Hi, as in subject. -- FFmpeg = Fantastic and Fabulous Monstrous Powerful Enigmatic Governor

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