VSPP Stuff

Scripts and tools related to VSPP.

It's usually crap but if it works, it works :-)

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Contents

This is the stuff that's in this repo.

1. segment_analyser.sh - A small script to pick out all the segments from a manifest file.
2. extract.py - small crappy python to extract frame details from a file.

segment_analyser.sh

The script can use a file that's already been downloaded from VSPP or it can fetch the manifest itself given the correct details. It returns the adaptation sets and the segments within that set. i.e.

Adaptation Set = video Segment_1 = 20000000 2 00h:00m:02s video Segment_2 = 40000000 4 00h:00m:04s video Segment_3 = 60000000 6 00h:00m:06s video

Adaptation Set = trickmode Segment_1 = 20000000 2 00h:00m:02s trickmode Segment_2 = 40000000 4 00h:00m:04s trickmode Segment_3 = 60000000 6 00h:00m:06s trickmode

Adaptation Set = audio_482_eng Segment_1 = 48128 2 00h:00m:02s audio Segment_2 = 96256 4 00h:00m:04s audio Segment_3 = 144384 6 00h:00m:06s audio

If the file has already been downloaded from VSPP use SublimeText 3 and format the file using IndentXML to make it nice and pretty. The script won't choke then.

GOPInfo.py (formerly extract.py)

GOPInfo.py will use ffprobe (if installed) to generate a file that shows GOP lengths and provides the pts value for each I-Frame. The ffprobe command used is:

ffprobe -select_streams v -show_frames -show_entries frame=pts,pkt_duration,pkt_pos,pict_type,pkt_size -v quiet -print_format json

this will first generate a json file with the usual ffprobe format:

{ "frames": [ { "pts": 172080, "pkt_duration": 1800, "pkt_pos": "23124", "pkt_size": "89017", "pict_type": "I", "side_data_list": [ { "side_data_type": "Active format description", "active_format": 10 } ] },

This is mostly for reference as the actual work is done in memory but, if a file is too big it might be necessary to read the file rather than do it all in memory.

From the results of ffprobe a text file will be generated (and will be displayed to screen too) with the following format:

15 8599680 IBBPBBPBBPBBPBB 15 8653680 IBBPBBPBBPBBPBB 15 8707680 IBBPBBPBBPBBPBB 16 8761680 IBBPBBPBBPBBPBBP 17 8819280 IBBPBBPBBPBBPBPBB 15 8880480 IBBPBBPBBPBBPBB 26 8934480 IBBPBBPBBPBBPBBPBBPBBPBBPP

This shows the GOP length, the pts value for the I-frame and the frame sequence until the next I-frame.

*** NOTE

segment_analyser doesn't work with the new format of manifest file. It's super annoying.

Old Version:

<SegmentTimeline>
	<S d="20000000" r="561"/>
	<S d="19200000"/>

New Version:

<SegmentTimeline>
	<S t="0" d="20000000" r="286" />
	<S t="5740000000" d="10000000" r="1" />

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