Bitrate Plotter
A command line program that plots one of the following graphs:
[1] A graph showing the bitrate every second. The graph can be "filled" or "unfilled".
[2] A graph showing bitrate of every closed GOP (you must specify the -gop argument). Applicable to video files only.
You can find an example of each graph type below:
Graph type [1] (unfilled):
![Graph type [1] (unfilled)](https://github.com/CrypticSignal/bitrate-variation-plotter/blob/main/Example%20Graphs/Bitrate%20every%20second%20(unfilled).png)
Image 1: a graph showing the bitrate every second. To see an example of a filled graph, check out the "Example Graphs" folder.
Graph type [2]:
![Graph type [2]](https://github.com/CrypticSignal/bitrate-plotter/blob/main/Example%20Graphs/Closed%20GOP%20bitrates.png)
Image 2: a graph showing the bitrate of every closed GOP. The distances between the lines show the length (in seconds) of each closed GOP.
When opting for graph type [1], the data used to plot the graph is saved in a filed named BitrateEverySecond.txt. The data is in the format timestamp --> bitrate. Here is a sample:
1.008 --> 223 kbps
2.016 --> 257 kbps
3.0 --> 239 kbps
4.008 --> 250 kbps
5.016 --> 263 kbps
6.0 --> 253 kbps
7.008 --> 264 kbps
8.016 --> 267 kbps
9.0 --> 260 kbps
10.008 --> 266 kbps
When opting for graph type [2], the raw FFprobe output is saved in a file named Keyframes & GOPs.txt. Each line in this file represents a frame, and you can see the following data:
- Whether the frame is a keyframe (if you see
key_frame=1, that frame is a keyframe). - The timestamp of the frame (
pts_pkt_time). - The size of the frame in bytes (
pkt_size).
You can find an example line below:
key_frame=1,pkt_pts_time=0.000000,pkt_size=250439
Requirements
- Python 3.6+
- FFprobe executable in your PATH.
pip install -r requirements.txt
Usage
You can find the output of python main.py -h below:
usage: main.py [-h] -f FILE_PATH [-g {filled,unfilled}] [-gop] [-se SHOW_ENTRIES] [-ngm] [-s STREAM_SPECIFIER]
optional arguments:
-h, --help show this help message and exit
-f FILE_PATH, --file-path FILE_PATH
Enter the path of the file that you want to analyse. If the path contains a space, it must be
surrounded in double quotes. Example: -f "C:/Users/H/Desktop/my file.mp4"
-g {filled,unfilled}, --graph-type {filled,unfilled}
Specify the type of graph that should be created. The default graph type is "unfilled". To see
the difference between a filled and unfilled graph, check out the example graph files.
-gop Instead of plotting the bitrate every second, plot the bitrate of each GOP. This plots GOP end
time (x-axis, in seconds) against GOP bitrate (y-axis, kbps).
-se SHOW_ENTRIES, --show-entries SHOW_ENTRIES
Only applicable if --no-graph-mode is specified. Use FFprobe's -show_entries option to specify
what to output. Example: -se frame=key_frame,pkt_pts_time
-ngm, --no-graph-mode
Enable "no graph mode" which simply writes the output of ffprobe to a .txt file. You should
also use the --show-entries argument to specify what information you want ffprobe to output.
-s STREAM_SPECIFIER, --stream-specifier STREAM_SPECIFIER
Use FFmpeg stream specifier syntax to specify the audio/video stream that you want to analyse.
The defaults for audio and video files are a:0 and V:0, respectively. Note that stream index
starts at 0. As an example, to target the 2nd audio stream, enter: --stream-specifier a:1