Author Topic: JVT/AVC Coding in QuickTime Inspector  (Read 582 times)

vangelis

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JVT/AVC Coding in QuickTime Inspector
« on: February 04, 2017, 08:51:22 AM »
Hi there,

I'm using avidemux to remux mkv into mp4 (m4v) using the mp4v2 mixer. When I open the resulting mp4 file in QT the inspector shows Format: JVT/AVC Coding, while when using the mp4v1 mixer for the same file, QT shows Format: H.264

Does anyone know what the difference is ? And where is "JVT/AVC Coding" coming from?

Thank you.
V

Jan Gruuthuse

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Re: JVT/AVC Coding in QuickTime Inspector
« Reply #1 on: February 04, 2017, 11:11:13 AM »
Quote
H.264/AVC is a video codec developed by the Joint Video Team (JVT); a cooperation between the ITU-T VCEG (Video Coding Experts Group) and ISO/IEC MPEG (Moving Picture Experts Group)
Perhaps OS related (Inspector reporting)? Have no clue what inspector is?

AQUAR

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Re: JVT/AVC Coding in QuickTime Inspector
« Reply #2 on: February 04, 2017, 12:12:33 PM »
H.264 is often called AVC Advanced Video Codec.
Different "inspectors" will report either convention accordingly.

dosdan

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Re: JVT/AVC Coding in QuickTime Inspector
« Reply #3 on: February 05, 2017, 03:24:31 AM »
And JVT is "Joint Video Team":

https://en.wikipedia.org/wiki/H.264/MPEG-4_AVC

For example, here is the start of the report from Avinaptic about a MP4 from my Panansonic HC-V750 camcorder:

Code: [Select]
About file

Name                        S3350001.MP4
Date                        Sat, 04 Feb 2017 11:38:41 +1000
Size                        3,728,027,769 bytes (3555.324334 MiB)

Magic

File type                   ISO Media, MPEG v4 system, version 2

Generic infos

Duration                    00:11:01 (660.66 s)
Container                   MP4/MOV
Major brand                 ISO Base Media version 1
Compatible brands           JVT AVC
Creation time               Sat, 04 Feb 2017 21:38:41 +1000
Modification time           Sat, 04 Feb 2017 21:38:41 +1000
Total tracks                2
Track nr. 1                 video (avc1) []
Track nr. 2                 audio (mp4a) []

Dan.
« Last Edit: February 05, 2017, 03:27:16 AM by dosdan »

eumagga0x2a

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Re: JVT/AVC Coding in QuickTime Inspector
« Reply #4 on: February 05, 2017, 11:02:07 AM »
I'm using avidemux to remux mkv into mp4 (m4v) using the mp4v2 mixer. When I open the resulting mp4 file in QT the inspector shows Format: JVT/AVC Coding, while when using the mp4v1 mixer for the same file, QT shows Format: H.264

Does anyone know [...] where is "JVT/AVC Coding" coming from?

This entry originates from avidemux_plugins/ADM_muxers/muxerMp4v2/libmp4v2/src/atom_avc1.cpp:50 of the bundled libmp4v2. The system libmp4v2 e.g. on Fedora, which is newer than the version supplied with Avidemux, includes the same code, so it doesn't matter if Avidemux was built using the bundled or an external libmp4v2 here.

vangelis

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Re: JVT/AVC Coding in QuickTime Inspector
« Reply #5 on: February 05, 2017, 11:41:02 AM »
Brilliant! Thank you for your clear answer.

Do you know of any other muxer that uses the libmp4v2? CLI or GUI for the mac?

TA,
V

eumagga0x2a

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Re: JVT/AVC Coding in QuickTime Inspector
« Reply #6 on: February 05, 2017, 11:48:24 AM »
Do you know of any other muxer that uses the libmp4v2? CLI or GUI for the mac?

Well, according to https://trac.macports.org/ticket/19141 at least the Mac port of the MPEG4ip library depends on libmp4v2. Which CLI or GUI tools use it, is up to your googling.

vangelis

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Re: JVT/AVC Coding in QuickTime Inspector
« Reply #7 on: February 05, 2017, 12:11:57 PM »
I'm not aware of the MPEG4ip library, do you know whether ffmpeg or MP4Box use libmp4v2?

TA,
V

eumagga0x2a

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Re: JVT/AVC Coding in QuickTime Inspector
« Reply #8 on: February 05, 2017, 02:57:43 PM »
do you know whether ffmpeg or MP4Box use libmp4v2?

Neither FFmpeg nor MP4Box uses libmp4v2 (at least AFAIK). In turn, MP4Box relies on FFmpeg.