h26x-extractor

Author: Werner Robitza

Extracts NAL units from H.264 bitstreams and decodes their type and content, if supported.

Note: This is not a replacement for a proper tool like h264bitstream. h26x-extractor is not fast and not robust, but rather a playground for parsing bitstreams. Use with caution!

Installation

Python 2.7:

pip install h26x-extractor

Python 3.x:

pip3 install h26x-extractor

Status

Currently supported:

Parsing of H.264 bitstreams
Parsing of NALU
Parsing of AUD
Parsing of CodedSliceIDR
Parsing of CodedSliceNonIDR
Parsing of SPS
Parsing of PPS

Currently planned:

Parsing of SEI
Parsing of VUI
Parsing of H.265 bitstreams

Usage

h26x-extractor [options] <input-file>...

You can pass the -v flag to enable verbose output, e.g. the following. You will get, for each NAL unit:

The bye position range
The offset from the start of the stream
The overall length including start code
The type (also translated in plaintext)
Its content in raw bytes, encoded as hex
Its RBSP content
A table with its content decoded, if supported

Example:

NALU bytepos:   [0, 28]
NALU offset:    0 Bytes
NALU length:    29 Bytes (including start code)
NALU type:      7 (Sequence parameter set)
NALU bytes:     0x0000000167f4000d919b28283f6022000003000200000300641e28532c
NALU RBSP:      0xf4000d919b28283f602200000002000000641e28532c

SPS (payload size: 22.0 Bytes)
+--------------------------------------+---------+
| field                                | value   |
+======================================+=========+
| constraint_set0_flag                 | 0       |
+--------------------------------------+---------+
| constraint_set1_flag                 | 0       |
+--------------------------------------+---------+
....

Programmatic usage

You can also use this library in your code, e.g.:

from h26x_extractor.h26x_parser import H26xParser

H26xParser.set_callback("nalu", do_something)
H26xParser.parse()
def do_something(bytes):
  # do something with the NALU bytes

Valid callbacks are:

sps
pps
slice
aud
nalu

Raw data for all callbacks includes the RBSP.

You can also call the nalutypes classes to decode the individual fields, e.g. nalutypes.SPS.

License

The MIT License (MIT)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.