Video file manipulation
The mg.utils.video module contains utility classes using ffmpeg to:
- parse video files,
- generate snapshot still images (thumbnails),
- transcode video.
The main entry point is the VideoHandler class.
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class mg.utils.video.VideoHandler[source]
A Video handler class. This object can help manipulate a video file.
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__init__(video_filename)[source]
Creates a new handler.
| Parameters: |
- video_filename (str) – File name containing the source video.
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streams[source]
list of StreamInfo object containing definition
of all the streams contained in the file.
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container[source]
Container type name (eg “avi” or “mov”).
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bit_rate[source]
File’s global bitrate (float), in bits/sec
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duration[source]
File run length (float), in seconds
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get_streams(type)[source]
Retrieve the streams of a given type.
| Parameters: |
- type (str) – Type of stream to get (eg “video” or “audio”)
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| Returns: | a list of StreamInfo objects.
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has_video()[source]
Returns whether this file contains at least one video stream.
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snapshot(output_file, image_size=None, time_offset=None, rot_count=0)[source]
This function calls a video thumbnailer tool to create a
thumbnail of the video as a still image file. The only
supported output format is JPEG.
| Parameters: |
- output_file (str) – File name of the image file to
create. This file name must contain a
valid JPEG file extension.
- image_size (tuple or None) – A (width, height) couple of integer sizes.
Leave to None to get an image of original size.
- time_offset (int or float or None) – A number of seconds to take the snapshot
at, from the start of stream. If offset is
beyond end of file or None, set it at
1/4th of the file.
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| Raises : | RuntimeError if thumbnail generation failed.
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| Raises : | ValueError if the input file has no video stream
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transcode(output_file, container_name, vs_info, as_info, rot_count=0, add_flags='')[source]
This function calls a video transcoding tool to create another
version of the same video.
| Parameters: |
- output_file (str) – File name of the image file to
create.
- container_name (str) – Name of the container format for
output_file.
- vs_info (VideoStreamInfo) – Video stream format
- as_info (AudioStreamInfo) – Audio stream format
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| Raises : | RuntimeError if thumbnail generation failed.
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| Raises : | ValueError if the input file has no video stream
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class mg.utils.video.StreamInfo[source]
A stream information base class.
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type
Type string (eg “video” or “audio”)
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format
A format short-name
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format_map
Static member, dict.
A dictionary mapping format names to codec to use for encoding.
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dest_args()[source]
Creates an argument list of ffmpeg command line for this stream.
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class mg.utils.video.AudioStreamInfo[source]
An Audio stream information class. Inherits StreamInfo.
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__init__(format, samplerate, channels, precision)[source]
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samplerate
Sample rate (float), in samples/sec
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channels
Count of simultaneous channels in this stream.
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precision
integer, in bits per sample.
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class mg.utils.video.VideoStreamInfo[source]
A Video stream information class. Inherits StreamInfo.
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__init__(format, size, fps, bitrate=None, dar=None, **kwargs)[source]
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size
Image size in a (width, height) couple
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fps
Frames per second (float)
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dar
Display aspect ratio (float). width/height ratio in visual
size.
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bitrate
Bitrate of the video stream. in bit/sec.