[FFmpeg-trac] #472(undetermined:open): Initial gray frames when first frame is no keyframe

[FFmpeg]

#472: Initial gray frames when first frame is no keyframe
-------------------------------------+-------------------------------------
             Reporter:  DonMoir      |                    Owner:
                 Type:  defect       |                   Status:  open
             Priority:  normal       |                Component:
              Version:  git-master   |  undetermined
             Keywords:               |               Resolution:
             Blocking:               |               Blocked By:
Analyzed by developer:  0            |  Reproduced by developer:  1
-------------------------------------+-------------------------------------
Changes (by cehoyos):

 * status:  new => open
 * version:  unspecified => git-master
 * reproduced:  0 => 1


Comment:

 mplayer trains_cut.flv shows no initial gray frames.
 {{{
 $ ffmpeg -i trains_cut.flv -qscale 2 out.avi
 ffmpeg version N-32617-ge78d1a5, Copyright (c) 2000-2011 the FFmpeg
 developers
   built on Sep 15 2011 23:18:20 with gcc 4.5.3
   configuration: --cc=/usr/local/gcc-4.5.3/bin/gcc --enable-gpl --enable-
 version2
   libavutil    51. 16. 0 / 51. 16. 0
   libavcodec   53. 15. 0 / 53. 15. 0
   libavformat  53. 12. 0 / 53. 12. 0
   libavdevice  53.  3. 0 / 53.  3. 0
   libavfilter   2. 40. 0 /  2. 40. 0
   libswscale    2.  1. 0 /  2.  1. 0
   libpostproc  51.  2. 0 / 51.  2. 0
 [flv @ 0x1301760] warning: first frame is no keyframe

 Seems stream 0 codec frame rate differs from container frame rate: 1000.00
 (1000/1) -> 25.00 (25/1)
 Input #0, flv, from 'trains_cut.flv':
   Metadata:
     audiodatarate   : 64
     framerate       : 25
     datasize        : 14613960
     lasttimestamp   : 212960
     audiosize       : 1802309
     videosize       : 12811397
     metadatacreator : inlet media - FLVTool2
     height          : 480
     filesize        : 14667897
     videodatarate   : 479
     duration        : 213
     encoder         : Riva FLV Encoder
     width           : 640
   Duration: 00:03:33.00, start: 0.000000, bitrate: 78 kb/s
     Stream #0.0: Video: flv1, yuv420p, 640x480, 490 kb/s, 25 tbr, 1k tbn,
 1k tbc
     Stream #0.1: Audio: mp3, 44100 Hz, mono, s16, 64 kb/s
 [buffer @ 0x1306ec0] w:640 h:480 pixfmt:yuv420p tb:1/1000000 sar:0/1
 sws_param:
 Incompatible sample format 's16' for codec 'ac3', auto-selecting format
 'flt'
 Output #0, avi, to 'out.avi':
   Metadata:
     audiodatarate   : 64
     framerate       : 25
     datasize        : 14613960
     lasttimestamp   : 212960
     audiosize       : 1802309
     videosize       : 12811397
     metadatacreator : inlet media - FLVTool2
     height          : 480
     filesize        : 14667897
     videodatarate   : 479
     duration        : 213
     width           : 640
     ISFT            : Lavf53.12.0
     Stream #0.0: Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 640x480,
 q=2-31, 200 kb/s, 25 tbn, 25 tbc
     Stream #0.1: Audio: ac3 ([0] [0][0] / 0x2000), 44100 Hz, mono, flt,
 128 kb/s
 Stream mapping:
   Stream #0.0 -> #0.0 (flv -> mpeg4)
   Stream #0.1 -> #0.1 (mp3 -> ac3)
 Press [q] to stop, [?] for help
 [flv @ 0x1301760] warning: first frame is no keyframe
 [flv @ 0x1301760] Error at MB: 567 3912kB time=00:00:24.31
 bitrate=1318.1kbits/s
 [flv @ 0x1301760] concealing 698 DC, 698 AC, 698 MV errors
 frame=  646 fps=396 q=2.0 Lsize=    4404kB time=00:00:25.87
 bitrate=1394.1kbits/s
 video:3957kB audio:404kB global headers:0kB muxing overhead 0.975746%
 }}}

-- 
Ticket URL: <https://avcodec.org/trac/ffmpeg/ticket/472#comment:4>
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