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how to get a sample mp4/aac audio file with chapter?
zhangweiwu
post Feb 6 2014, 06:26
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QUOTE
Under iOS and OS X, chapter marks in MP4 files (with URLs and images) are generally well supported by most podcast players, for example in Apple's Podcast app. MP3 chapters can be displayed with the recommended Instacast and Downcast (both with URLs and images).
On Android you can use the open source AntennaPod to display chapter marks with URLs in MP3 and Ogg Vorbis files.
-- Chapter Marks for MP3, MP4 Audio and Vorbis Comment (Enhanced Podcasts) , Auphonic Blog.


I have never seen an MP4 file with chapter-mark - having played more than 1000 mp4 files in my life. I wish to have one to test on my devices. Most podcasts are blocked outright from China, hence I never enjoyed them on iOS, and even if I can workaround the national firewall's sensorship, I still prefer to have a solid file in my hard-disk that I can dissect and study. For example, wikipedia quoted two methods to add chapter mark to MP4 container: formatted text track and userdata atom. I wish to find out which one is supported by which device. Furthermore if I produce chapter-mark in a mp4 file and it doesn't work, I need to compare it with a sample file that works.

Thanks for hints and download link offerings! If there were none, it helps the public to make sample MP4s out of opensource clips, right?

P. S. Since .mp4 format can contain chapter mark as well as MPEG-2 Part-2 Video codec, the same video codec in DVDs, it seems to be an ideal method to archive DVDs without re-encoding and retain playback ability. Why, that I have never seen a DVD archived in mp4 format for the last a few decades? I see more frequently DVDs are re-encoded in AVI formats, with chapter marks lost; and in ratDVD format, also re-encoded; and finally ISO format, which only a handful of players can handle without unpacking.

This post has been edited by zhangweiwu: Feb 6 2014, 06:33
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sundance
post Feb 6 2014, 07:30
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I don't know if there are downloads of chaptered mp4 files available, but you can easily create one.
All you need is foobar or QAAC:
CODE
qaac.exe --concat -o S:\test.mp4 file1.flac file2.flac file3.flac

You'll get a file like that (mediainfo output):
CODE
General
Complete name                            : S:\test.mp4
Format                                   : MPEG-4
Format profile                           : Apple audio with iTunes info
Codec ID                                 : M4A
File size                                : 22.0 MiB
Duration                                 : 15mn 15s
Overall bit rate mode                    : Variable
Overall bit rate                         : 201 Kbps
Encoded date                             : UTC 2014-02-06 06:19:56
Tagged date                              : UTC 2014-02-06 06:20:30
Writing application                      : qaac 2.33, CoreAudioToolbox 7.9.8.5, AAC-LC Encoder, TVBR q91, Quality 96

Audio
ID                                       : 1
Format                                   : AAC
Format/Info                              : Advanced Audio Codec
Format profile                           : LC
Codec ID                                 : 40
Duration                                 : 15mn 15s
Bit rate mode                            : Variable
Bit rate                                 : 200 Kbps
Maximum bit rate                         : 233 Kbps
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 44.1 KHz
Compression mode                         : Lossy
Stream size                              : 21.8 MiB (99%)
Encoded date                             : UTC 2014-02-06 06:19:56
Tagged date                              : UTC 2014-02-06 06:20:30

Menu #1
ID                                       : 2
Codec ID                                 : text
Duration                                 : 15mn 15s
Encoded date                             : UTC 2014-02-06 06:20:30
Tagged date                              : UTC 2014-02-06 06:20:30
Bit rate mode                            : CBR
Duration_FirstFrame                      : -209640
Duration_LastFrame                       : -16027

Menu #2
00:00:00.047                             : File1
00:02:50.914                             : File2
00:09:11.421                             : File3

Afaik, audiobooks purchased in iTunes come as chaptered m4b files.

.sundance.

This post has been edited by sundance: Feb 6 2014, 07:42
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zhangweiwu
post Jun 9 2014, 15:23
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Thank you for being so detail to include the commandline. I forgot to mention I am on Ubuntu Linux, and qaac command doesn't seem to exist for me. I did some google study and found the Linux equivalent seems to be mp4chaps.

I successfully produced chapter-marked mp4 files this way (using 'mp4chap -i' to import mp4.chapters.txt file) and chapter marks are usable with VLC (desktop edition). The chapter marks are not recognized by Android 4.4.2 as I tested. Strange enough, there is no way to skip chapter marks even in iOS, be it Nero chapter marks or the apple-invented Quicktime chapter marks - using the "Video" app shiped with iOS. One of course expect Apple's mobile support Apples' feature. Perhaps iTunes playback can handle the chapter marks, but then I do not know how to copy the content into iTunes instead of "Videos" app.

This post has been edited by zhangweiwu: Jun 9 2014, 15:30
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