42、 ffmpeg 的简单使用
一、FFmpeg-python 安装
pip3 install ffmpeg-Python
也可以通过克隆源码返回式进行安装：
git clone git@GitHub.com:kkroening/ffmpeg-python.git
export PYTHONPATH=${PYTHONPATH}:ffmpeg-python
python
>>> import ffmpeg
>>> help(ffmpeg) # 通过help()可以查看ffmpeg提供的相应的Python api
二、常用的ffmpeg 的python API
1、probe 获取视频文件的详细信息
语法格式：
probe(filePath[, cmd="ffprobe"])
用于获取视频文件的详细信息，filePath是文件路径的字符串表示。[...]中的内容可选，一般使用默认值。其返回值是一个字典，字典中有两个key-value对。
示例
import ffmpeg
info = ffmpeg.probe("/xxx/xxx/test.mp4")
"""
{
"streams": [
{
"index": 0,
"codec_name": "h264",
"codec_long_name": "H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10",
"profile": "Main",
"codec_type": "video",
"codec_time_base": "1001/48000",
"codec_tag_string": "avc1",
"codec_tag": "0x31637661",
"width": 1024,
"height": 576,
"coded_width": 1024,
"coded_height": 576,
"has_b_frames": 1,
"sample_aspect_ratio": "1:1",
"display_aspect_ratio": "16:9",
"pix_fmt": "yuv420p",
"level": 31,
"color_range": "tv",
"color_space": "bt709",
"color_transfer": "bt709",
"color_primaries": "bt709",
"chroma_location": "left",
"refs": 1,
"is_avc": "true",
"nal_length_size": "4",
"r_frame_rate": "24000/1001",
"avg_frame_rate": "24000/1001",
"time_base": "1/48000",
"start_pts": 0,
"start_time": "0.000000",
"duration_ts": 2883840,
"duration": "60.080000",
"bit_rate": "944746",
"bits_per_raw_sample": "8",
"nb_frames": "1515",
"disposition": {
"default": 1,
"dub": 0,
"original": 0,
"comment": 0,
"lyrics": 0,
"karaoke": 0,
"forced": 0,
"hearing_impaired": 0,
"visual_impaired": 0,
"clean_effects": 0,
"attached_pic": 0,
"timed_thumbnails": 0
},
"tags": {
"language": "und",
"handler_name": "Video Media Handler"
}
},
{
"index": 1,
"codec_name": "aac",
"codec_long_name": "AAC (Advanced Audio coding)",
"profile": "LC",
"codec_type": "audio",
"codec_time_base": "1/44100",
"codec_tag_string": "mp4a",
"codec_tag": "0x6134706d",
"sample_fmt": "fltp",
"sample_rate": "44100",
"channels": 2,
"channel_layout": "stereo",
"bits_per_sample": 0,
"r_frame_rate": "0/0",
"avg_frame_rate": "0/0",
"time_base": "1/44100",
"start_pts": 0,
"start_time": "0.000000",
"duration_ts": 2646441,
"duration": "60.010000",
"bit_rate": "125617",
"max_bit_rate": "125617",
"nb_frames": "2721",
"disposition": {
"default": 1,
"dub": 0,
"original": 0,
"comment": 0,
"lyrics": 0,
"karaoke": 0,
"forced": 0,
"hearing_impaired": 0,
"visual_impaired": 0,
"clean_effects": 0,
"attached_pic": 0,
"timed_thumbnails": 0
},
"tags": {
"language": "und",
"handler_name": "GPAC ISO Audio Handler"
}
}
],
"fORMat": {
"filename": "/Users/didi/Desktop/Python/python3/code/section_35/data/1.mp4",
"nb_streams": 2,
"nb_programs": 0,
"format_name": "mov,mp4,m4a,3gp,3g2,mj2",
"format_long_name": "QuickTime / MOV",
"start_time": "0.000000",
"duration": "63.189000",
"size": "8500415",
"bit_rate": "1076189",
"probe_score": 100,
"tags": {
"major_brand": "isom",
"minor_version": "512",
"compatible_brands": "isomiso2avc1mp41",
"encoder": "Lavf58.20.100"
}
}
}
"""
输入结果如下：
{
'streams': [{'index': 0, 'codec_name': 'h264', ...}]
'format': {'filename': '/Users/didi/isp-system/data/test_video.mp4', ...}
}
其中key：‘streams’对应的值是一个list，list中有两个dict类型的值，分别表示视频中视频流和音频流的相关信息。
key：‘format’对应的值是一个dict，其中包含了视频的相关的格式信息、视频时长信息、文件大小信息等。
我们可以通过一下代码获取我们关心的信息：
info = ffmpeg.probe(str(file))
vs = next(c for c in info['streams'] if c['codec_type'] == 'video')
duration_secs = float(vs['duration'])
format = info['format']['format_name']
codec_name = vs['codec_name']
width = vs['width']
height = vs['height']
num_frames = vs['nb_frames']
2、input(filePath, **kwargs)
输入文件的路径。
ffmpeg.input(filename, **ffmpeg_args)
ffmpeg.input()等价与在命令行输入ffmpeg -i ...kwargs中可以包含的参数有：t、f、acodec等
一般与output、run联合使用。
3、output(*streams_and_filePath, **kwargs)
输入文件的路径。
ffmpeg.output(stream1[, stream2, stream3...], filename, **ffmpeg_args)
kwargs中可以包含的参数有：t、f、acodec、vcodec等
一般与output、run联合使用。
4、run(stream_spec, cmd='ffmpeg', capture_stdout=False, capture_stderr=False, input=None, quiet=False, overwrite_output=False)
为提供的节点图调用ffmpeg
综合示例一：对视频文件进行全抽帧
import ffmpeg
# 全抽帧
def get_frames():
input_file = '/Users/didi/Desktop/ffmpeg/test.mp4'
output_file = '/Users/didi/Desktop/ffmpeg/image/image-%5d.jpg'
out, err = (
ffmpeg
.input(input_file)
.output(output_file)
.run(quiet=False, overwrite_output=True)
)
if out == b'':
print('do nothing')
# 按一定的频率抽帧
def get_frames_by_rate():
input_file = '/Users/didi/Desktop/ffmpeg/test.mp4'
output_file = '/Users/didi/Desktop/ffmpeg/image/image-%5d.jpg'
out, err = (
ffmpeg
.input(input_file, ss=0)
# .output(output_file, r='1', f='image2')
.output(output_file, vf='fps=fps=1', f='image2')
.run(quiet=False, overwrite_output=True)
)
if out == b'':
print('do nothing')
# 按指定时间片段抽帧
def get_frames_by_times():
times = [1, 5, 8, 10]
for time in times:
input_file = '/Users/didi/Desktop/ffmpeg/test.mp4'
output_file = '/Users/didi/Desktop/ffmpeg/image/image-' + str(time) + '.jpg'
out, err = (
ffmpeg
.input(input_file, ss=time)
.output(output_file, vframes='1', f='image2')
.run(quiet=False, overwrite_output=True)
)
if out == b'':
print('do nothing')
if __name__ == '__main__':
get_frames_by_rate()
5、concat(*streams, **kwargs)
连接音频和视频流，将它们一个接一个地连接在一起。
import ffmpeg
# 视频剪切
def cut_videos():
input_file = '/Users/didi/Desktop/ffmpeg/test.mp4'
output_file = '/Users/didi/Desktop/ffmpeg/video/video1.mp4'
out, err = (
ffmpeg
# 注意ss，t的单位都是秒
.input(input_file, ss=220, t=20)
.output(output_file, codec="copy")
.run(quiet=False, overwrite_output=True)
)
if out == b'':
print('do nothing')
# 视频合并
def concat_video():
# 注意：要合并的视频文件和txt文件需要放在同一个目录下
input_file = '/Users/didi/Desktop/ffmpeg/video/aa.txt'
output_file = '/Users/didi/Desktop/ffmpeg/video/Cam.mp4'
try:
out, err = (
ffmpeg
.input(input_file, f='concat')
.output(output_file, c='copy')
.run(quiet=False, overwrite_output=True)
)
except Exception as e:
print(e)
if __name__ == '__main__':
concat_video()
#cut_videos()
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