Convert AVCHD to MP4 without quality loss

Tractor Shark

Novice Member
Hi guys
I wonder if anyone can help me with this please.
Please bear with me. I'm not a technical wizard but I want to give you as much info as possible.
I have a Panasonic HDC-SD90 Full HD camcorder. I used to take the AVCHD footage off the camcorder and edit it through the Panasonic software HD Writer AE 3.0. I'd then burn it to a disk which I'd play on a Sony Blu-Ray player. Apart from it being a slow process, this worked fine.
However.....
We have just bought a new computer with Windows 10 (replacing our old Vista one).
Before I switched computers, I saved all the video on to a memory stick and then transferred it all to the new computer.
It plays fine in HD on the new computer except when a clip ends it doesn't start the next one, despite me selecting Play All.
This is where the problem lies. When I put the memory stick in my TV (Sony KDL 46HX753), the clips play one after the other BUT there is an annoying pause between each one. Basically the screen goes black, a circle whirls for a few seconds while it loads up the next clip before restarting again.
The disks I used to burn had a very minimal pause between each clip, but this appears to be loading each file individually.
The quality is fine, though.
My son told me the answer to this problem was to convert all the clips from AVCHD to MP4. He did this (I think via Format Factory and VLC??) but, although the clips played seemlessly, the quality had clearly dropped. It didn't look HD anymore.
He also tried creating a playlist, it involved rendering I think, but again the quality had dropped.
I tried installing the old Panasonic software HD Writer 3.0 on the new computer but, while it successfully installed albeit with a couple of error messages, it would not register the video folders so I couldn't use it.

My questions are:
Is there a way of converting these AVCHD video files so I can play them seemlessly on my TV through a USB stick without losing the Full HD quality?
Are we doing something wrong?
Is there another software package either free or paid for that could achieve this? The guy at PC suggested Adobe Premiere Elements.

I'm sure there must be a solution to this. It's incredibly frustrating having an HD Camcorder taking beautiful footage that looks great on an HD TV but is spoiled by constant interruptions while files load.

Any help you can give would be greatly appreciated.
Thank you
 

Music Fan

Active Member
There are several ways to do it, you can use TSmuxer to join these files (they must have the same characteristics).
If you need mp4 container, you can use Yamb (or Avidemux). I don't remember if Yamb can open TS container ; if not, demux with TSmuxer first (after joining files) to get elementary streams, then use Yamb.

Other trick to know about AVCHD : when you film for a long time, the title (clip) will probably be divided in 2 GB chunks. The best way to copy these chunks is to open in TSmuxer the mpls file (located in PLAYLIST folder) corresponding to this title instead of opening one by one and joining the m2ts files.
Then TSmuxer will join them automatically and properly (export in TS or M2ts).

If your TV supports AVCHD format (on SD card, USB key or external HDD), you can also put directly your SD card into it.
But if you need to join files already on your pc, you can make an AVCHD with TSmuxer. If your TV supports only FAT32 and if there are titles bigger than 4 GB in your project, check "split by size every" and choose 4 GB in "split & cut" tab. The cuts will be invisible (thanks to the playlist file, same principle than ifo on dvd for 1 GB sized VOBs).

You can do the same for a Blu-ray player supporting AVCHD (if it does, it will probably also play it from HDD, if it has a USB port of course).
 
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rogs

Well-known Member
My son told me the answer to this problem was to convert all the clips from AVCHD to MP4.....

The simplest way of doing that - without any loss video of quality - is to download the free MKVtoMP4 converter utility from HERE

No need to install it - it's a portable application - just download and open it.

Then simply drag and drop your .mts or .m2ts file into the window and press 'start'.
The program will re-encode your audio from AC3 to AAC (standard format for mp4 audio) but will not re-encode the video. So it's quick and the result is visually identical.

As I say , that's the simplest way I can think of.
Nothing wrong with using the alternatives suggested above of course...
 
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Tractor Shark

Novice Member
The simplest way of doing that - without any loss video of quality - is to download the free MKVtoMP4 converter utility from HERE

No need to install it - it's a portable application - just download and open it.

Then simply drag and drop your .mts or .m2ts file into the window and press 'start'.
The program will re-encode your audio from AC3 to AAC (standard format for mp4 audio) but will not re-encode the video. So it's quick and the result is visually identical.

As I say , that's the simplest way I can think of.
Nothing wrong with using the alternatives suggested above of course...


Thank you for your replies. Can I check this download will work with Windows 10?
 

rogs

Well-known Member
I'm not running Windows 10 here, so I can't confirm whether it will work with that or not.
As its not an installed program - and it's free! - it might be worth a try anyway?
If not, there are several options from Music Fan's post to try out....
 

Music Fan

Active Member
TSmuxer is very simple too and re-encodes neither video nor audio.
I'm partisan of the less re-encoding possible, except when unavoidable.
 

rogs

Well-known Member
TSmuxer is very simple too and re-encodes neither video nor audio.
I'm partisan of the less re-encoding possible, except when unavoidable.

I agree, but the SD90 audio will be AC3, and mp4 videos with AC3 audio can't be played in quicktime, iTunes, as well as ipad, iphones, ipods, Apple TV, some TV USB ports etc, etc...

Converting the audio to AAC makes it much more compatible for mp4 replay. Loss of audio quality in that conversion will normally be negligible....
Not converting the video, on the other hand is much more important.
The simple utility I suggested will convert the audio - but not the video. You can of course manually change the settings to keep the AC3 audio if you wish, but the default AAC conversion is probably a better choice for this task......
 

Music Fan

Active Member
Yes, it really depends on the OP's goal and the capacities of his equipment.
 

carlozdre

Standard Member
The simplest way of doing that - without any loss video of quality - is to download the free MKVtoMP4 converter utility from HERE

No need to install it - it's a portable application - just download and open it.

Then simply drag and drop your .mts or .m2ts file into the window and press 'start'.
The program will re-encode your audio from AC3 to AAC (standard format for mp4 audio) but will not re-encode the video. So it's quick and the result is visually identical.

As I say , that's the simplest way I can think of.
Nothing wrong with using the alternatives suggested above of course...

Do you know of a similar alternative for OSX?
 

rogs

Well-known Member
No sorry, I'm not wealthy enough to be a mac user - :) - so I'll have to leave this to our mac experts to advise you...
 

Music Fan

Active Member
Yes :)
tsMuxer has a GUI, ffmpeg is used in command line (not that complicated).
tsMuxer cannot create mp4 (it does ts or m2ts) but it's good to join files, then ffmpeg can be used to change the container if mp4 is needed (and it can maybe join files too in the same process but I never tried this).
There is also MKVToolNix if you need MKV ;
MKVToolNix Downloads – Matroska tools for Linux/Unix and Windows
Anyway, if your source is an AVCHD folder with long titles divided in several m2ts, the first step is to use tsMuxer (to open the mpls and join properly the m2ts, as I explained in my first answer).
 
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12harry

Distinguished Member
tsMuxer is the way to join files as others have suggested, but it's a rather quirky free piece of software. What it does it does well, but I really wonder if OP is finding fault where none exists.?

All video clips can be improved by Editing and then Render to the mp4 or m2ts - and it should play all the way - but Editing gives him the option of adding Titles and maybe some music . . . Transition between scenes also helps to make the film "interesting" -

<< I used to think mp4 was "better" than m2ts - but a recent short video rendered in both shows the mp4 as 65Mb and the m2ts as 51Mb - yet there was no "obvious" quality difference . . . is there more to this?>>

Long movies can be Rendered overnight to HDD ( a reasonably fast external drive if HDD space is pressing) . . . and then burn to DVD/BD as required . . . although USB Memory stick is likely to retain HD quality if the video is Rendered as 1920x1080.
- I've all but eliminated using DVDs as their ( lower ) playback quality is definitely visible.

Hope that helps . . . let us know how you get on.
 

dosdan

Active Member
Other trick to know about AVCHD : when you film for a long time, the title (clip) will probably be divided in 2 GB chunks. The best way to copy these chunks is to open in TSmuxer the mpls file (located in PLAYLIST folder) corresponding to this title instead of opening one by one and joining the m2ts files.
Then TSmuxer will join them automatically and properly (export in TS or M2ts).

Thanks for the tip. I tried this with the 28Mbps AVCHD files from my Panasonic HC-V750. The SDXC card is formatted as exFAT, so the camera is creating a new MTS every 3.98 GB (in true GB of 2^30 bytes, not 10^9 bytes). (BTW, 50Mbps MP4 files in this camera split every 3.47GB.) Here is the tsMuxeR screen, after I opened a playlist file which referred to 2 MTS files (41 mins total time), and then remuxed them as a M2TS:

TSMuxer%20Screen.jpg


The remux took 85 secs on my i5 PC. This was reading off the SD card (87 MB/s Read rate) on J:, an ext. USB3 card reader, and writing to the HDD, D:, so remuxing might have been quicker if reading from media files already situated on the HDD.

The HDD on the PC is formatted as NTFS and there was no problem storing the resultant single 7.15 GB M2TS file.

I then loaded the 2 MTS files and the resultant M2TS file into Sony Vegas Pro 12. Both worked well but there is a momentary loss in audio between the MTS files that were just appended, rather than being joined first via the playlist. The recording is of a TV news channel so there's constant speaking going on. Here is a MP3 comparing the audio transition between the 2 files in Vegas, first appended, then from the playlist-combined version from tsMuxeR. You can hear how in the phrase, "Over a late rental payment", the word "rental" is muted in the appended version. (You'll need to copy-and-paste the URL into your browser's address bar):

https:/dl.dropbox.com/s/ufw9scshg0l1n01/M2TS%20Join.mp3

A similar small inter-file audio loss occurs when appending multiple MP4 files.

Unfortunately, it appears Vegas 12 won't accept an AVCHD playlist. So use tsMuxeR first to parse it and to correctly combine the files, before loading the resultant media file in Vegas.

Dan.
 
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Music Fan

Active Member
Cool !
If one has already copied m2ts without the playlist, there is maybe a solution (which I never tried) to avoid gaps when joining them ;
demux all m2ts files and remux separately audio and video (to get one long audio file and one long video file), then remux audio and video.
I don't remember if TSMuxer can join only audio files ; if not, do it in mka with MKVMerge, then demux the mka with MKVExtract to get an ac3 file and load this ac3 in TSMuxer (or load the mka in TSMuxer if accepted).
 

dosdan

Active Member
If one has already copied m2ts without the playlist, there is maybe a solution (which I never tried) to avoid gaps when joining them

I found out that it's Sony Vegas that's dropping off the audio at the end-of-file when I import the MTS files. If instead I append within tsMuxeR, they will be joined without a loss without using a playlist. For example, in an empty Input Files list in tsMuxR, I used the "Add' button to add 37.MTS. Then I used the "Join" button to append 38.MTS, selected M2TS as the Output format and finally clicked on "Start muxing" to process.

So you can combine AVCHD files successfully without a playlist. Of course, using the playlist file makes it easier, particularly if it's a long recording and there are a number of MTS files.

Of interest, in tsMuxer I can't combine MP4 files, sourced from a camera, as described above. It gets half-way through the processing and then aborts with a "moov atom not found" error. The cause of this error is explained here:

How to fix a broken MP4/MOV video (ffmpeg reports "moov atom not found") | monline

I tried the videorepair program downloaded from the dropbox link mentioned on that page on the MP4 file, but I think it's too old. tsMuxeR wouldn't load the fixed files. Vegas loads the fixed files with full-duration video, but with half-duration audio i.e. the second half of each fixed clip had no sound.

Dan.
 
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alleyn

Novice Member
I tried installing iDealshare VideoGo. It is very easy to convert AVCHD to MP4, FLV, SWF, MOV, VOB, MXF, DVR, RMVB, DV, MKV, MVI and etc. You may have a try.:)
 

rogs

Well-known Member
Cant' see why anyone is going to pay for that software, when the programs described above do the job for free? -

And it's not a quality issue... there's no video re-encoding involved...
 

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