How to convert 1080@50i -> 720@50p using ffmpeg?

Question

I really like 50fps video, but I cannot make ffmpeg convert it to 50fps for me.

720p resolution is absolutely fine with me, just need more FPS.

50i just looks much smoother in proper players (for example GOM Player deinterlaces video and plays it at 50Hz. Very big difference to 25Hz video.)...

My current command line is:

ffmpeg -i 00010.MTS -threads 3 -filter:v yadif -s "1280x720" -r 50 -b:v 20M output.avi

Here are more video details. Source video is from Cannon HF10 AVCHD camcoder.

ffmpeg -i 00010.MTS -threads 3 -filter:v yadif -s "1280x720" -r 50 -b:v 20M output.avi
ffmpeg version N-37541-g670229e Copyright (c) 2000-2012 the FFmpeg developers
  built on Feb  3 2012 20:14:17 with gcc 4.6.2
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-ru
ntime-cpudetect --enable-avisynth --enable-bzlib --enable-frei0r --enable-libope
ncore-amrnb --enable-libopencore-amrwb --enable-libfreetype --enable-libgsm --en
able-libmp3lame --enable-libopenjpeg --enable-librtmp --enable-libschroedinger -
-enable-libspeex --enable-libtheora --enable-libvo-aacenc --enable-libvo-amrwben
c --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxavs --enable-
libxvid --enable-zlib
  libavutil      51. 37.100 / 51. 37.100
  libavcodec     54.  0.102 / 54.  0.102
  libavformat    54.  0.100 / 54.  0.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 61.100 /  2. 61.100
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0.  6.100 /  0.  6.100
  libpostproc    52.  0.100 / 52.  0.100
[h264 @ 000000000033FA30] Increasing reorder buffer to 1
Input #0, mpegts, from '00010.MTS':
  Duration: 00:03:13.92, start: 0.482156, bitrate: 16304 kb/s
  Program 1
    Stream #0:0[0x1011]: Video: h264 (High) (HDMV / 0x564D4448), yuv420p, 1920x1
080 [SAR 1:1 DAR 16:9], 50 fps, 50 tbr, 90k tbn, 50 tbc
    Stream #0:1[0x1100]: Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, stereo, s16,
256 kb/s
File 'output.avi' already exists. Overwrite ? [y/N] y
w:1920 h:1080 pixfmt:yuv420p tb:1/1000000 sar:1/1 sws_param:
[yadif @ 0000000003CE95B0] mode:0 parity:-1 auto_enable:0
[scale @ 0000000003CE9550] w:1920 h:1080 fmt:yuv420p -> w:1280 h:720 fmt:yuv420p
 flags:0x4
Output #0, avi, to 'output.avi':
  Metadata:
    ISFT            : Lavf54.0.100
    Stream #0:0: Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 1280x720 [SAR 1:1 DA
R 16:9], q=2-31, 20000 kb/s, 50 tbn, 50 tbc
    Stream #0:1: Audio: mp3 (U[0][0][0] / 0x0055), 48000 Hz, stereo, s16, 128 kb
/s
Stream mapping:
  Stream #0:0 -> #0:0 (h264 -> mpeg4)
  Stream #0:1 -> #0:1 (ac3 -> libmp3lame)
Press [q] to stop, [?] for help
frame=   15 fps=  0 q=2.0 size=     945kB time=00:00:00.62 bitrate=12481.3kbits/
frame=   32 fps= 32 q=2.0 size=    2132kB time=00:00:01.30 bitrate=13435.2kbits/
frame=   51 fps= 34 q=2.0 size=    3372kB time=00:00:02.06 bitrate=13409.2kbits/
frame=   70 fps= 35 q=2.0 size=    4641kB time=00:00:02.82 bitrate=13482.8kbits/
frame=   76 fps= 35 q=2.0 Lsize=    5047kB time=00:00:03.06 bitrate=13511.9kbits

Solution 1

"For most practical cases it is not possible to retrieve a complete progressive video from interlaced content."

Also if you could upload a small sample of the video, it would help your cause tremedously.

Source: mplayerhq.hu/DOCS/HTML/en/menc-feat-telecine.html

Solution 2

Just like interlacing progressive content divides each frame into 2 fields, thus doubling the frame rate, the common method of deinterlacing is to combine each 2 fields into 1 frame, which reduces the rate by 2, thus taking 50 into 25fps. You can of course double each final frame, but that does not provide any benefit.

First, we can read not to use -deinterlace, and yadif instead (which you already do):

 - deinterlace This option is deprecated since the deinterlacing is very low quality. Use the yadif filter with -filter:v yadif. 

You'll probably find the the yadif section of the FFMPEG documentation pretty interesting:

Deinterlace the input video ("yadif" means "yet another deinterlacing filter"). 
It accepts the optional parameters: mode:parity:auto. 

MODE specifies the interlacing mode to adopt, accepts one of the following values: 
‘0’
output 1 frame for each frame
‘1’
output 1 frame for each field 
‘2’
like 0 but skips spatial interlacing check 
‘3’
like 1 but skips spatial interlacing check 
Default value is 0. 

PARITY default value is -1.
AUTO default value is 0. 

Notice how the default MODE is 0, which instructs FFMPEG to ouput 1 frame for each 2 fields, thus halving the fps. I think what you're looking for is MODE 1: one frame per field. I'm not too sure how to use these optional parameters but perhaps something like

-filter:v yadif 1:-1:0 -s "1280x720" -r 50 

Solution 3

ffmpeg -i input.avi -deinterlace -filter:v yadif -s "1280x720" output.avi

Solution 4

According to the documentation, the -r option sets the output file frames per second. For example, this sets the output to 50 frames per second:

ffmpeg -i input.avi -r 50 output.avi

View more solutions

Comments

[Admin]

What do you mean, 'cannot make'? Does it give you errors?

[Admin]

It produces file, which looks like 25p, not as smoooth as 50i in proper player.

[Admin]

@slhck Here it goes

[Admin]

Any specific reason for encoding to MPEG-4 Visual instead of using h.264 again (e.g. -vcodec libx264? Not that it should matter that much at ~20 MBit/s, but still.

[Admin]

@slhck well, it's just default :-)

[Admin]

What happens if you use ffmpeg with "-r 100" ? Why don't you use mencoder with -vf scale=width:height ?

[Admin]

Well, in mediainfo file have 100 FPS, but I am still getting just 25 FPS on the player. When stepping frame by frame it's exactly 25 FPS.

[Admin]

Does mencoder manage to do a better job of driving ffmpeg ?

[BarsMonster]

Unfortunately, the file produced is about the same as for -r 25. And it's not longer smoooth. It looks like it just took 25p video, and then framedoubled it.

[Just Jake]

Have you tried specifying input framerate as well?

[Jason]

That is excpeted. When you deinterlace video you sacrifice smooth motion for compatibly with progressive displays.

[BarsMonster]

Unfortunately, it still produced just 25 fps output... Original file is way way smoother.... Even adding -r 50 didn't helped.

[BarsMonster]

@Jason Well, my videoplayer (GOM Player) deinterlaces 50i video, and shows it smoothly (i.e. at 50Hz) on my 120Hz TFT monitor, which is obviously progressive. Why can't video recoder do the same thing, and produce smooth 50Hz output? I understand that 50i have less small details, but why can't I expect to get 50Hz output?

[slhck]

It depends on the deinterlacing filter used. Obviously GOM Player does a good job at this. Don't know too much about how FFmpeg handles interlaced video though. @BarsMonster

[BarsMonster]

At least it gives 50 fps output, but unfortunately 2 sequential frames generated are very similar... While when I step original 50i video frame by frame I really see that fast motion have twice more 'steps', and much smoother.

[mtone]

@BarsMonster First, I'd try to find out what GOM player does, in case it's due to some form of interpolation. I'm curious - is there that much interlaced content that contains high-fps information? (After all, converting a 25p to 50i for broadcasting does not create any new motion information - you need straigth-to-interlaced content). Next, if you do find a deinterlacting technique that GOM uses (see wikipedia, there are quite a few), you should try to find a filter for it that can be used in AVISYNTH as part of the process instead of using FFMPEG's -YADIF method.