AVCHD to QT and Avid

[bouke]

Trying to convert various flavours of AVCHD (.mts) into QT for AMA import /
link in Avid.
Simple -vcodec copy -acodec pcm_s16le.
No errors whatsoever, and the files play fine in QT / VLC, but Avid
introduces artefacts (dropped frames, blockyness)
Stepping backwards frame by frame seem to be better, perhaps that's a clue..

Any ideas if this is even possible without a transcode?

thx,
Bouke


What i'm doing:
FFMBC.exe -i "N:\02\New folder\AR25MAY064.MTS" -vcodec copy -acodec
pcm_s16le "N:\02\New folder\AR25MAY064.mov""

FFmbc version 0.7-rc7

Copyright (c) 2008-2012 Baptiste Coudurier and the FFmpeg developers

Input #0, mpegts, from 'N:\02\New folder\AR25MAY064.MTS':

Duration: 00:02:25.02, start: 0.476222, bitrate: 16061 kb/s

Program 1

Stream #0.0[0x1011](und): Video: h264 (High), yuv420p, 1920x1080i tff [PAR
1:1 DAR 16:9], 25.00 fps

Stream #0.1[0x1100](und): Audio: ac3, 48000 Hz, stereo, s16, 256 kb/s

Stream #0.2[0x1200](und): Subtitle: pgssub

[pcm_s16le @ 03702CC0] The requested thread algorithm is not supported with
this thread library.

Output #0, mov, to 'N:\02\New folder\AR25MAY064.mov':

Metadata:

encoder: FFmbc 0.7

Stream #0.0(und): Video: h264, yuv420p, 1920x1080i tff [PAR 1:1 DAR 16:9],
stream copy, 25.00 fps

Stream #0.1(und): Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s

Stream mapping:

Stream #0.0 -> #0.0

Stream #0.1 -> #0.1

Press [q] to stop, [?] for help

frame= 2255 fps=1127 size= 176253kB time=00:01:29.95 bitrate=16051.5kbits/s
eta=00:00:01.22

[mov @ 0037F9C0] color primaries unspecified, assuming bt709

frame= 3624 fps=1094 Lsize= 291985kB time=00:02:24.92 bitrate=16505.2kbits/s

video:264774kB audio:27186kB global headers:0kB muxing overhead 0.008513%

[oskarsum...@gmail.com]

Why do you want to edit in h.264? It's a recipe for pain. Stop being precious and just transcode the damn thing.

-stib

[bouke]

----- Original Message -----
From: <oskarsum...@gmail.com>
To: <ffmbc-...@googlegroups.com>
Cc: <bo...@editb.nl>
Sent: Tuesday, October 02, 2012 4:52 PM
Subject: [ffmbc-discuss] Re: AVCHD to QT and Avid


> Why do you want to edit in h.264? It's a recipe for pain. Stop being
> precious and just transcode the damn thing.
>
> -stib

Stib,
You're missing a couple of points here:
-It's not always up to me to decide. Others decide for me, and i'm asked to
advice.
-Some people have no trouble working with the files. Premiere seems to do a
decent job on a fast machine. (and some edits are really simple, just top /
tail)
-The current case is that Avid and AVCHD don't play well together.
Client has TONS of this stuff (and other formats) on near line storage. They
transcode all to an offline codec in Avid.
Then for online, they restore just the used clips, AMA them in and transcode
the used stuff to something good.
Now transcoding the AVCHD to something easier would increase the amount on
their near line storage, or (in case the transcode should be to an offline
codec for Avid),
involves a huge risk of not being able to relink.
(avid relinks based on duration of the file. With these files there is a
risk of an 'off by one' error. Stupid, i know, but i'ts the way it is....)
So it would mean transcoding the whole shebang twice, one for offline, one
for online.
That would be my choice as well, as storage is relative cheap, and a render
farm isn't that expensive as well, but if the client decides, i'll bug you
to make it happen :-)

Does that make sense?

Bouke

[Phil Rhodes]

> Why do you want to edit in h.264? It's a recipe for pain. Stop being precious and just

> transcode the damn thing. It is very dangerous to assume you know everything about someone else's use case. P

[Baptiste Coudurier]

On 10/02/2012 12:45 AM, bouke wrote:
> Trying to convert various flavours of AVCHD (.mts) into QT for AMA import /
> link in Avid.
> Simple -vcodec copy -acodec pcm_s16le.
> No errors whatsoever, and the files play fine in QT / VLC, but Avid
> introduces artefacts (dropped frames, blockyness)
> Stepping backwards frame by frame seem to be better, perhaps that's a clue..
>
> Any ideas if this is even possible without a transcode?

It is possible since QT plays it well. Avid might require some special information in the .mov
file to decode the file correctly due to PAFF. Do you have a file that works, I could investigate.

--
Baptiste COUDURIER
Key fingerprint 8D77134D20CC9220201FC5DB0AC9325C5C1ABAAA
FFmpeg maintainer http://www.ffmpeg.org

[bouke]

----- Original Message -----
From: "Baptiste Coudurier" <baptiste....@gmail.com>
To: <ffmbc-...@googlegroups.com>
Sent: Friday, October 12, 2012 6:38 AM
Subject: Re: [ffmbc-discuss] AVCHD to QT and Avid


> On 10/02/2012 12:45 AM, bouke wrote:
>> Trying to convert various flavours of AVCHD (.mts) into QT for AMA import
>> /
>> link in Avid.
>> Simple -vcodec copy -acodec pcm_s16le.
>> No errors whatsoever, and the files play fine in QT / VLC, but Avid
>> introduces artefacts (dropped frames, blockyness)
>> Stepping backwards frame by frame seem to be better, perhaps that's a
>> clue..
>>
>> Any ideas if this is even possible without a transcode?
>
> It is possible since QT plays it well. Avid might require some special
> information in the .mov
> file to decode the file correctly due to PAFF. Do you have a file that
> works, I could investigate.

Baptiste,
Thanks for looking into this. What i don't get, why do you want a file that
works?
(I would think a file that does not work would be handy...)
Meanwhile, it turns out that MC 6.x DOES work. So perhaps it's a bug in
Avid.
With this knowledge, do you still want to work on it?
And, what the hell is PAFF?
I'll see if i can find a file that does work, but no guarantees i'll find
one.
(not working files are easy :-)

Bouke