[FFmpeg-devel] [PATCH] avformat/segment.c: add experimental -segment_list_flags iframe

[Michael Niedermayer]

On Wed, May 21, 2014 at 01:33:52AM -0700, Aman Gupta wrote:
> The HLS spec supports [I-FRAMES-ONLY playlists][1] where BYTERANGEs
> represent locations of keyframes inside mpegts segments. These are used
> by iOS devices to show previews when a user seeks around a stream.
> 
> Apple's mediafilesegmenter can generate iframe.m3u8s alongside regular
> playlists with --iframe-index-file. The stream and iframe playlists
> share ts segments, with the iframe playlist pointing to the keyframes in
> the stream. This would be a useful feature for ffmpeg, but is not
> implemented by this patch.
> 
> Instead, I added a new `-segment_list_flags iframe` mode where
> a dedicated playlist and segment is generated just for previewing.
> A single .ts file is sufficient (as the playlist uses byteoffsets), and
> it contains only keyframes (making it a fraction the size of the
> original stream).
> 
> Here's how to generate iframe.m3u8 and iframe0.ts for an h264 input.
> Notice that I only map the video stream into the segmenter.
> 
>   ./ffmpeg -i input.mkv -map 0:0 -c:v copy -bsf:v h264_mp4toannexb \
>            -f stream_segment -segment_format mpegts \
>            -segment_list iframe.m3u8 -segment_list_flags iframe iframe%d.ts

why not use "-skip_frame nokey" if you want to create a file made
from the keyframes ?

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Freedom in capitalist society always remains about the same as it was in
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