On 12/13/18, Kieran O'Leary <kieran.ole...@irishfilm.ie> wrote: > Hi, > > I have encountered some DPX that has an fps of 18. It seems that ffmpeg > skips every few frames when decoding - at least when I performed a framemd5 > analysis. I noticed that 30522 frames were decoded, 10172 were dropped. > > It seems that adding -framerate 18 to as an input option resolves the issue, > but should ffmpeg not auto-detect the FPS? > > I can replicate the issue with just a few frames (I will see if I can share > the samples) - here's 17 frames decoded with nullm followed by the md5 muxer > where only 14 frames are processed.: > > $ ./ffmpeg -i ffmpeg-1-01_%06d.dpx -f null - > > ffmpeg version N-92683-g32601fb821 Copyright (c) 2000-2018 the FFmpeg > developers > > built with Apple LLVM version 8.0.0 (clang-800.0.42.1) > > configuration: > > libavutil 56. 24.101 / 56. 24.101 > > libavcodec 58. 42.100 / 58. 42.100 > > libavformat 58. 24.100 / 58. 24.100 > > libavdevice 58. 6.101 / 58. 6.101 > > libavfilter 7. 46.101 / 7. 46.101 > > libswscale 5. 4.100 / 5. 4.100 > > libswresample 3. 4.100 / 3. 4.100 > > Input #0, image2, from 'ffmpeg-1-01_%06d.dpx': > > Duration: 00:00:00.68, start: 0.000000, bitrate: N/A > > Stream #0:0: Video: dpx, gbrp10le, 3840x2160, 18 tbr, 25 tbn, 18 tbc > > Stream mapping: > > Stream #0:0 -> #0:0 (dpx (native) -> wrapped_avframe (native)) > > Press [q] to stop, [?] for help > > Output #0, null, to 'pipe:': > > Metadata: > > encoder : Lavf58.24.100 > > Stream #0:0: Video: wrapped_avframe, gbrp10le, 3840x2160, q=2-31, 200 > kb/s, 18 fps, 18 tbn, 18 tbc > > Metadata: > > encoder : Lavc58.42.100 wrapped_avframe > > [null @ 0x7f88d3000600] Application provided invalid, non monotonically > increasing dts to muxer in stream 0: 1 >= 1 > > [null @ 0x7f88d3000600] Application provided invalid, non monotonically > increasing dts to muxer in stream 0: 4 >= 4 > > [null @ 0x7f88d3000600] Application provided invalid, non monotonically > increasing dts to muxer in stream 0: 6 >= 6 > > [null @ 0x7f88d3000600] Application provided invalid, non monotonically > increasing dts to muxer in stream 0: 9 >= 9 > > frame= 17 fps=0.0 q=-0.0 Lsize=N/A time=00:00:00.72 bitrate=N/A speed= > 1.1x > > video:9kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing > overhead: unknown > > > $ ./ffmpeg -i ffmpeg-1-01_%06d.dpx -f md5 - > > ffmpeg version N-92683-g32601fb821 Copyright (c) 2000-2018 the FFmpeg > developers > > built with Apple LLVM version 8.0.0 (clang-800.0.42.1) > > configuration: > > libavutil 56. 24.101 / 56. 24.101 > > libavcodec 58. 42.100 / 58. 42.100 > > libavformat 58. 24.100 / 58. 24.100 > > libavdevice 58. 6.101 / 58. 6.101 > > libavfilter 7. 46.101 / 7. 46.101 > > libswscale 5. 4.100 / 5. 4.100 > > libswresample 3. 4.100 / 3. 4.100 > > Input #0, image2, from 'ffmpeg-1-01_%06d.dpx': > > Duration: 00:00:00.68, start: 0.000000, bitrate: N/A > > Stream #0:0: Video: dpx, gbrp10le, 3840x2160, 18 tbr, 25 tbn, 18 tbc > > Stream mapping: > > Stream #0:0 -> #0:0 (dpx (native) -> rawvideo (native)) > > Press [q] to stop, [?] for help > > Output #0, md5, to 'pipe:': > > Metadata: > > encoder : Lavf58.24.100 > > Stream #0:0: Video: rawvideo (G3[0][10] / 0xA003347), gbrp10le, > 3840x2160, q=2-31, 4478976 kb/s, 18 fps, 18 tbn, 18 tbc > > Metadata: > > encoder : Lavc58.42.100 rawvideo > > frame= 5 fps=0.0 q=-0.0 size= 0kB time=00:00:00.27 bitrate= > 0.0kbits/frame= 9 fps=7.5 q=-0.0 size= 0kB time=00:00:00.50 > bitrate= 0.0kbits/frame= 12 fps=7.0 q=-0.0 size= 0kB > time=00:00:00.66 bitrate= 0.0kbits/MD5=123fb3ff58ca94c842453b518aeb6a9a > > frame= 14 fps=6.6 q=-0.0 Lsize= 0kB time=00:00:00.77 bitrate= > 0.4kbits/s dup=0 drop=3 speed=0.364x
Here it says it dropped 3 frames. > > video:680400kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB > muxing overhead: unknown This is because null does not need timestamps so it pass all frames no matter which timestamps are there, on other hand md5 drops frames with same timestamps. _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
