[FFmpeg-devel] rawvideo bitrate?

Tim leopdong
Thu Dec 4 07:00:24 CET 2008


  

here, I have a headache problem, maybe you can help me.

         

         I try to use ffmpeg to convert an 1920*1080 29.97fps video to an uncompressed video .

         My command : ffmpeg -i D:\temp\avi2bmp\Mantis.0000.ts -f rawvideo -vcodec rawvideo -sameq -r 29.97 g:\mantis.avi

         the bitrate=751274.3kbits/s

         

         but if we calculate the bitrate as below method , we should get 1.4 Gibps (1024-based)

         so I don?t understand why the 2 result are not the same. 

       

 

Input parameters

????

Pixel size:

wide x high 

????

Framerate:

FPS Interlaced 

Color model:

RGB 4:4:4 (common for computer)RGBA (RGB + Alpha channel)YUV 4:4:4 (high quality video)YUV 4:2:2 (common for video)YUV 4:1:1 (lower quality, high compression)YUV 4:2:0 (lower quality, high compression)CMYKRAW (Bayer mask)

Color depth:

bits/color 

????

 

 

 

Calculation  

One frame

Megapixels:

2,073,600 px

Uncompressed size:

6.22 MB
5.9 MiB (1024-based)
(24 bits/pixel)

Moving image

Pixel rate:

62.21 MHz

Uncompressed bitrate:

1.49 Gbps (standard SI-units)
= 186.62 MB/s
1.4 Gibps (1024-based)
(rgb444, 8 bits/comp, 30fps)

Required storage:
(uncompressed)

30 seconds:

5.60 GB

5.2 GiB

1 minute:

11.20 GB

10.4 GiB

5 minutes:

55.99 GB

52.1 GiB

1 hour:

671.85 GB

625.7 GiB

24 hours:

16.12 TB

14.7 TiB

 

 

 

         Below is the detail 

D:\ffmpeg>ffmpeg -i D:\temp\avi2bmp\Mantis.0000.ts -f rawvideo -vcodec rawvideo

-sameq -r 29.97 g:\mantis.avi

FFmpeg version SVN-r12665, Copyright (c) 2000-2008 Fabrice Bellard, et al.

  configuration: --enable-gpl --enable-postproc --enable-swscale --enable-avfilt

er-lavf --enable-pthreads --enable-liba52 --enable-avisynth --enable-libfaac --e

nable-libfaad --enable-libgsm --enable-memalign-hack --enable-libmp3lame --enabl

e-libnut --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libxvid

 --cpu=i686 --extra-ldflags=-static

  libavutil version: 49.6.0

  libavcodec version: 51.54.0

  libavformat version: 52.13.0

  libavdevice version: 52.0.0

  built on Apr  2 2008 22:35:11, gcc: 4.2.3

Input #0, mpegts, from 'D:\temp\avi2bmp\Mantis.0000.ts':

  Duration: 00:08:11.7, start: 92.610322, bitrate: 17466 kb/s

  Program 1

    Stream #0.0[0x11]: Video: mpeg2video, yuv420p, 1920x1088 [PAR 136:135 DAR 16

:9], 65000 kb/s, 29.97 tb(r)

    Stream #0.1[0x14]: Audio: liba52, 48000 Hz, stereo, 384 kb/s

File 'g:\mantis.avi' already exists. Overwrite ? [y/N] y

Output #0, rawvideo, to 'g:\mantis.avi':

    Stream #0.0: Video: rawvideo, yuv420p, 1920x1088 [PAR 136:135 DAR 16:9], q=2

-31, 200 kb/s, 29.97 tb(c)

Stream mapping:

  Stream #0.0 -> #0.0

Press [q] to stop encoding

frame=   87 fps= 29 q=0.0 Lsize=  266220kB time=2.9 bitrate=751274.3kbits/s

video:241740kB audio:0kB global headers:0kB muxing overhead 10.126582%

 

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------



More information about the ffmpeg-devel mailing list