Note: I posted same question to stackoverflow a short time before, when I have not found this comunity yet. I repost this since the question is more suitable to this community.
1. What I tried
I have some .MTS (AVCHD format) files recoreded with my AVCHD camera. Its specification is as shown below:
$ ffprobe 140612_Canon-00000.MTS ffprobe version 2.2.1 Copyright (c) 2007-2014 the FFmpeg developers (snip) Input #0, mpegts, from '140612_Canon-00000.MTS': Duration: 00:48:58.40, start: 0.800300, bitrate: 5563 kb/s Program 1 Stream #0:0[0x1011]: Video: h264 (High) (HDMV / 0x564D4448), yuv420p, 1440x1080 [SAR 4:3 DAR 16:9], 29.97 fps, 29.97 tbr, 90k tbn, 59.94 tbc Stream #0:1[0x1100]: Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, stereo, fltp, 256 kb/s
Pay attention to the part of framerate/timebase: 29.97 fps, 29.97 tbr, 90k tbn, 59.94 tbc
Now I’d like to convert this file to .mp4 file, without re-encoding H264 video stream, on the other hand, with transcoding its audio stream to AAC. So I tried the following command:
ffmpeg -i 140612_Canon-00000.MTS -t 60 -y -vcodec copy -acodec libfaac -ab 128k 140612_Canon-00001.MTS.mp4
and output file’s specification is as shown below:
$ ffprobe 140612_Canon-00000.MTS.mp4 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '140612_Canon-00000.MTS.mp4': Metadata: major_brand : isom minor_version : 512 compatible_brands: isomiso2avc1mp41 encoder : Lavf55.33.100 Duration: 00:01:00.04, start: 0.021333, bitrate: 4590 kb/s Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1440x1080 [SAR 4:3 DAR 16:9], 4448 kb/s, 59.94 fps, 59.94 tbr, 90k tbn, 59.94 tbc (default) Metadata: handler_name : VideoHandler Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default) Metadata: handler_name : SoundHandler
Look at the part of framerate/timebase: 59.94 fps, 59.94 tbr, 90k tbn, 59.94 tbc. Although ffmpeg just copied the video stream, framerate and timebase has been changed to twice value.
So, when I open and playback the output file with QuickTime Player or VLC Player, the audio has no problem, however, the video stream is not played correctly. The video is played back with having its frame forward and backward quiveringly repeatedly.
- How can I convert .MTS file (AVCHD) to .mp4 by ffmpeg without re-encoding H264 video stream correctly?
- How can I keep the original framerate/timebase values (fps/tbr/tbn/tbc) when I convert the container with
- How can I set framerate/timebase values (fps/tbr/tbn/tbc) by ffmpeg’s command line options without re-encoding a video stream.
-r 29.97 option
Professor Sparkles gave me an advice to add
-r 29.97. I tried that:
ffmpeg -i 140612_Canon-00001.MTS -t 60 -r 29.97 -y -vcodec copy -acodec libfaac -ab 128k 140612_Canon-00001.MTS.mp4
However, the output file has still wrong framerate/timebase:
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1440x1080 [SAR 4:3 DAR 16:9], 4448 kb/s, 59.94 fps, 59.94 tbr, 11988 tbn, 59.94 tbc (default)
5. Remux using MP4Box
I tried demux and remux using MP4Box, according to Professor Sparkles’s advice.
brew install mp4box ffmpeg -i 140612_Canon-00000.MTS -t 60 -y \ -vcodec copy -an 140612_Canon-00000.MTS.h264 ffmpeg -i 140612_Canon-00000.MTS -t 60 -y \ -vn -acodec libfaac -ab 128k 140612_Canon-00000.MTS.aac mp4box -add 140612_Canon-00000.MTS.h264:fps=29.97 \ -add 140612_Canon-00000.MTS.aac \ -new 140612_Canon-00000.MTS.mp4
and output was:
$ ffprobe 140612_Canon-00000.MTS.mp4
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '140612_Canon-00000.MTS.mp4': (snip) Duration: 00:02:00.22, start: 0.000000, bitrate: 2293 kb/s Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1440x1080 [SAR 4:3 DAR 16:9], 2228 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default) Metadata: creation_time : 2014-07-14 00:38:23 handler_name : 140612_Canon-00000.MTS.h264:fps=29.97 - Imported with GPAC 0.5.0-rev4065 Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 125 kb/s (default)
It looks a bit step forward.
Look at the part of framerate/timebase: 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc.
Those are match to the original stream, except for
tbn (timebase value from container).
However, when I play back the output file with Quicktime Player or VLC, the video is play back at the half speed.
Although the original file has
90k tbn (90000 ticks per second) and the new output file from MP4Box has
30k tbn which is just one-third value of original one, the output file is play back at the half speed.
I don't know the reason why. But I think the rest issue is how I can adjust the
5-b. MediaInfo's report on the output file
I also tried MediaInfo tool on the output file generated by 5. Remux using MP4Box. The output is here: https://gist.github.com/kaorukobo/c5ab9eaa413dff6cd26a
6. Trying avconv
avconv worked well. Also I prepared a short sample movie file (Canon-00006.MTS) recorded with the same camera. Okay, let's try:
brew install avconv avconv -i Canon-00006.MTS -c:a copy -c:v copy -y Canon-00006.MTS.mp4 ffprobe Canon-00006.MTS.mp4
The output file's ffprobe information is here: https://gist.github.com/kaorukobo/5b53244ade2632ff1211 and its framerate/timebase information is as the following: 59.94 fps, 59.94 tbr, 90k tbn, 59.94 tbc
The output file was played back well with VLC Player as Volodya reported. However, opening it with Quicktime Player X, the video was play back at the normal speed but with having its frame backward quiveringly repeatedly.
7. Why "Free AVCHD to MOV" app work?
The software calls its own ffmpeg (or avconv) program internally, and I saw what options are passed to it. It's as shown below:
/Applications/Free AVCHD to Mov.app/Contents/Resources/bin/com.geranium-soft.convert \ -i /path/to/140710_Canon-00003.MTS \ -map 0:0 -map 0:1 -c:a libfaac -vol 256 -b:a 128k -c:v copy \ -sn -movflags faststart -threads 0 -pix_fmt yuv420p -y \ /path/to/140710_Canon-00003.mov
I tried passing same options (Extractly same. I set the output container type to MOV and removed even
-t 60 switch.) to ffmpeg program and converting. But the result was same as reported so far.
Anyway that great app resolved my issue on "How can I convert .MTS file (AVCHD) to .mp4 without re-encoding H264 video stream?", except at "to .mp4" and "by ffmpeg". But I'm still interested in why that app do well but ffmpeg don't.