I am cutting up bits of m2ts videos (AVCHD Lite: H264, 1280x720, 50.0FPS) shot on a Lumix DMC-TZ10 point 'n' shoot camera using Avidemux 2.6.8 (x64). Using default settings, all I do is set point A and B on the timeline. I am then saving the output as 'copy' both video and audio format - the decoder is 'lavcodec', the output format AVI muxer. My understanding is that no recoding takes place and a new AVI container is provided.
I use WMP12 for playback and it turns out that the new AVIs generated are sped up somewhat (say 1.2x even though both input and output is 50fps). Why would this be?
NB: no filters, such as 'change FPS' were used..
Many thanks for any help!
Our website is made possible by displaying online advertisements to our visitors.
Please consider supporting us by disabling your ad blocker or buy PlayOn (record Netflix) :)
Please consider supporting us by disabling your ad blocker or buy PlayOn (record Netflix) :)
+ Reply to Thread
Results 1 to 30 of 30
Just installed MPCHC and it turn out that input is fine, output is still sped up. So its either the input file or Videoremux...
Am reading up about AVCHD Lite and 'frame repeat flag' (thanks!)..
Is it possible that Avidemux does not handle these files too well? Hopefully there's a workaround..
ps: trying other containers.
yes , avidemux can be a bit buggy, it might be having problems with avchd lite. Make sure you're cutting on keyframes (use the "<<" and ">>" buttons in the GUI to navigate before marking in/out)
you can also try tsmuxer, but it cuts by timecodes (no preview), but it should preserve the frame repeat flag
ok, other containers are not applicable or do not save correctly. Transcoding seems ok (tried mpeg4 avcx264), but of course editing now takes time. Hmmm..
avidemux can be very buggy at times. I was just playing with an avchd lite sample and it seems to mangle it. I guess you can't complain too much with freeware.
Re-encoding isn't ideal, because you incur quality loss unless you use a lossless codec (huge filesizes), and you lose quality again when re-encoding to the final lossy format. Conversely, stream copying is faster, no quality loss
ffmpeg seems to be able to copy segments out fine, but it's commandline usage only , no preview
Note none of these free tools are frame accurate - they only cut on I-frame boundaries. If you're looking at something precise you need a smart editor that re-encodes the few frames around a cutsite if it's no on an I-frame boundary eg. videoredo, solveigmm video splitter . If it's something you're going to be doing frequently you might want to have a look at one of the trials
^ ok, cross-posts! Thanks for your ideas!
hmmm tsmuxer worked ok on a sample from a Lumix TZ7, it was a "60p" sample (30p with frame repeat flag) .
ffmpeg worked ok here too. To use ffmpeg you need to specify a start time -ss and duration -t . e.g. copy a segment from 1min to 1min30sec for a duration of 30sec
ffmpeg -i input.mts -c:v copy -c:a copy -ss 00:01:00 -t 00:00:30 output.ts
But maybe something else is peculiar about your camera or files ?
Last edited by poisondeathray; 28th Jul 2014 at 17:13.
Your initial description made me think that your player was ignoring the frame repeat flag. That means it plays back at 50fps, but with only "25FPS" worth of frames. But if that were the case it would play at exactly 2x speed, not 1.2x speed
btw, what is the best way to extract information from a video file? i.e. whether it has 'repeat frame flags', fps, ratio, audio tyoe, AVCHDLite or other HD format etc?
ok, will post back tomorrow. G'day!
Did the original, uncut ,native files play ok in MPCHC on your system ?
Without a doubt, "AVCHD Lite" is only 25p (or 30p) with the frame repeat flag. Thats is 100% certain because that's in the specs. The marketing "geniuses" call it 720p50 or 720p60 because it sounds better and might sell more cameras
That 0.5x speed is suspicious number, and it suggests that the frame repeat flag might have something to do with it. If the software completely ignores the flag, and plays back at the proper framerate of 25 fps, then everything is ok. But if it ignores the flag, and "thinks" it's a 50p file, then you get the double speed playback
If you check in mediainfo, it will call it "frame doubling" in the frame mode entry
Format/Info : Advanced Video Codec Format profile : High@L4.0 Format settings, CABAC : No Format settings, ReFrames : 1 frame Frame mode : Frame doubling
Last edited by poisondeathray; 28th Jul 2014 at 17:51.
Sorry for my absence; work took over!
* The original uncut files play ok in MPCHC and other videoplayers.
* I have not been able to try VideoRedo or Solveigmm as trial versions that I installed over a year ago have expired.
* Media Info of input file (Pana AVCHDLite):
Format : BDAV Format/Info : Blu-ray Video File size : 154 MiB Duration : 1mn 33s Overall bit rate mode : Variable Overall bit rate : 13.9 Mbps Maximum Overall bit rate : 18.0 Mbps Video ID : 4113 (0x1011) Menu ID : 1 (0x1) Format : AVC Format/Info : Advanced Video Codec Format profile : High@L4.0 Format settings, CABAC : No Format settings, ReFrames : 1 frame Frame mode : Frame doubling Format settings, GOP : M=1, N=13 Codec ID : 27 Duration : 1mn 33s Bit rate mode : Variable Bit rate : 13.1 Mbps Maximum bit rate : 16.6 Mbps Width : 1 280 pixels Height : 720 pixels Display aspect ratio : 16:9 Frame rate : 25.000 fps Standard : NTSC Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Bits/(Pixel*Frame) : 0.570 Stream size : 146 MiB (95%)
Format : AVI Format/Info : Audio Video Interleave File size : 36.0 MiB Duration : 11s 460ms Overall bit rate mode : Variable Overall bit rate : 26.4 Mbps Video ID : 0 Format : AVC Format/Info : Advanced Video Codec Format profile : High@L4.0 Format settings, CABAC : No Format settings, ReFrames : 1 frame Frame mode : Frame doubling Format settings, GOP : M=1, N=13 Codec ID : H264 Duration : 11s 460ms Bit rate mode : Variable Bit rate : 25.9 Mbps Maximum bit rate : 16.6 Mbps Width : 1 280 pixels Height : 720 pixels Display aspect ratio : 16:9 Frame rate : 50.000 fps Original frame rate : 25.000 fps Standard : NTSC Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Bits/(Pixel*Frame) : 0.563 Stream size : 35.4 MiB (98%)
* both videos are in NTSC format [would this really matter?]
* the 'double frame rate' flag has NOT disappeared in the output file but the FPS is now 50 (25 in original).
I'll mull this over and see what else I can find out.
Note - Mediainfo isn't always correct - it often misreports (it should say "PAL", but it's not really "PAL" either, as that more appropriately applies to SD)
Avidemux is probably reading the field rate, not the frame rate, you would need to force it to 25 fps . That didn't occur with the 29.97p "AVCHD Lite" (or fake 59.94) sample I cut - it didn't become 59.94 so it wasn't sped up - but it botched other things like the audio. I used avidemux 2.6.4. I see there is a 2.6.8 version I see now it might work better or worse. Avidemux can be very flaky/buggy. Certain versions work ok others crap out
If the cut file is otherwise fine, you can force the framerate in something like mkvtoolnix if you don't mind mkv container (it's better for h.264 anyway)
Dear Poisondeathray. Thanks for the suggestion of the MKVtoolnix. I can indeed change the FPS to 25 of the avidemux output file, but (as yet) am not sure the audio stretch of 2 has the desired (i.e normal) result I'm after.
BTW if I rewrap my avchd input to an MKV container I can no longer use Avidemux to clip these files (it is impossible to set A and B, or scroll fwd etc).
As I'm trying to keep my work flow as simple as possible (there are A LOT of AVCHDLite files to go through!), I was wondering whether to rewrap or correct (if that's the word) all my panasonic avchd input files in batch manner - that's before I start clipping with Avidemux. Is there such a tool that could do that - ffmpeg for instance?
Once again, many thanks for your help.
You don't have to change the audio in mkvtoolnix , you can change the framerate of the video only
It should be possible to edit MKV in avidemux , it might be something buggy with that version
What did you want to batch re-wrap to ? MP4? MKV ?
From the commandline as a batch command
for %a in ("*.mts") do ffmpeg -i %a -c:v copy -c:v copy %~na.mkv pause
If you want to do it as a batch file, you need to replace each "%" with "%%"
If you want MP4, change the MKV extension to MP4
hmmm, I had to stretch the audio, because the audio stopped exactly halfway playback of the mkv file (it's difficult to check whether the audio is ok or not as it's just windnoise in my test file - I don't have my other avchd files at hand here on my work computer).
Will report back over the coming week.
So, a few things I have found out over the last days:
** Avidemux is pretty amazing when it comes to quickly cropping home videos on I-frames without recoding.
** Forcing the framerate to 25 fps should solve the problem (but haven't found out how to do this for the original file without rewrapping).
But why is this so?
What I have found out from wrapping the AVCHDLite m2ts files to the MKV container (using MKVtoolNix), cutting in avidemux and back to m2ts file (using tsMuxer) for cropping in Avidemux...
... is that the AVCHDLite file should have the framerate in the wrapper set at 12.5 fps for cropping and outputting in AVI (or other formats) in Avidemux to work! This indicates that information in the wrapper is incorrect or incorrectly read by Avidemux (and other software) resulting in not doubling of the fps, but quadrupling of the fps during playback..
Not too sure if that makes sense!
Video ID : 4113 (0x1011) Menu ID : 1 (0x1) Format : AVC Format/Info : Advanced Video Codec Format profile : High@L4.0 Format settings, CABAC : No Format settings, ReFrames : 1 frame Frame mode : Frame doubling Format settings, GOP : M=1, N=13 Codec ID : 27 Duration : 31s 180ms Bit rate mode : Variable Bit rate : 13.2 Mbps Maximum bit rate : 16.6 Mbps Width : 1 280 pixels Height : 720 pixels Display aspect ratio : 16:9 Frame rate : 25.000 fps Standard : NTSC Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Bits/(Pixel*Frame) : 0.571 Stream size : 49.0 MiB (94%)
> convert back to m2ts
Video ID : 4113 (0x1011) Menu ID : 1 (0x1) Format : AVC Format/Info : Advanced Video Codec Format profile : High@L4.0 Format settings, CABAC : No Format settings, ReFrames : 1 frame Frame mode : Frame doubling Format settings, GOP : M=1, N=13 Codec ID : 27 Duration : 14s 760ms Bit rate mode : Variable Bit rate : 13.2 Mbps Maximum bit rate : 16.6 Mbps Width : 1 280 pixels Height : 720 pixels Display aspect ratio : 16:9 Frame rate : 12.500 fps Standard : NTSC Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Bits/(Pixel*Frame) : 1.147 Stream size : 23.3 MiB (95%)
** Both input and output play fine in WMP and MPC-HC
** Only output file and not the input file can be cropped in Avidemux without changing playback fps of the final output!
avidemux has had problems with h264 & transport streams for the longest time. Sometimes it doubles the frame rate by reading the field rate instead of the frame rate
Give xmediarecode a try, it worked ok cutting some sample AVCHDLite clips from a TZ7 - you have a slightly different model, but they are both from Panasonic so there might be some hope
BTW - "cropping" in the video world usually refers to cutting in from the sides , ie. the peripheral borders of the video (left, top, right, bottom) - not making edits , like trimming clips with in/out points
Thanks for keeping up with this and the many suggestions. I'm learning whilst moving along!
-Avidemux is not the only software I have had the problem with, so it could be both the container and executing software I guess.
-The filters for the input in Avidemux only work when something is selected from the dropdown unfortunately. Otherwise I could enforce 25fps (which works, but recoding takes place..)
-Just installed Xmedia and it looks great! Many options indeed. Unfortunately the playback does not show in the window. This looks like a graphics card (i have two on this laptop) incompatibility with the software.
-Trying a trim (thanks for pointing out the correct terminology) without visual clues... works! output plays at expected fps, amazing.
Is there a way to cut at an I frame as in Avidemux?
This is actually my 1st time using it - I was testing it out for another thread
With the video selected, isn't there any preview in the filters/preview tab ?
It displays the frame type at the bottom, but you cannot navigate by keyframes with push of a button, only frame by frame.
If all you need is rough cuts, it doesn't matter where you cut, because it will automatically jump to the nearest keyframe anyways. For AVCHD lite , that is about 1/2 sec accuracy
EDIT: Make sure you close all other video applications before starting the program. Sometimes a video won't display if another app is using some resources like a shared renderer
You might try Free Video Editor but you'll need to be careful when installing it because it will install adware if you let it. Earlier versions of this software were very buggy but the latest version works much better with more options. I have had it cut videos that VideoReDo TV Suite had trouble with. The newest version allows you to make multiple cuts where earlier versions would crash if you tried to make more than one cut.