用ffmpeg获取帧数 [英] Fetch frame count with ffmpeg

问题描述

有人知道如何使用ffmpeg从视频文件中提取总帧数吗? ffmpeg的渲染输出显示当前帧，我需要帧计数来计算进度百分比.

Does anyone know how to fetch the number of total frames from a video file using ffmpeg? The render output of ffmpeg shows the current frame and I need the frame count to calculate the progress in percent.

推荐答案

注意:MP4/M4V/M4A/MOV中存在编辑列表会影响您的帧号.请参见下面的编辑列表.

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ffprobe:查询容器

Note: The presence of an edit list in MP4/M4V/M4A/MOV can affect your frame number. See Edit lists below.

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ffprobe: Query the container

ffprobe -v error -select_streams v:0 -show_entries stream=nb_frames -of default=nokey=1:noprint_wrappers=1 input.mp4

• 这是一种快速的方法.
• 并非所有格式(例如Matroska)都将报告导致输出N/A的帧数.请参阅下面列出的其他方法.
• This is a fast method.
• Not all formats (such as Matroska) will report the number of frames resulting in the output of N/A. See the other methods listed below.

ffprobe -v error -count_frames -select_streams v:0 -show_entries stream=nb_read_frames -of default=nokey=1:noprint_wrappers=1 input.mkv

• 这是一种缓慢的方法.
• 添加-skip_frame nokey选项以仅计算关键帧.
• This is a slow method.
• Add the -skip_frame nokey option to only count key frames.

如果您没有ffprobe，则可以改用ffmpeg:

If you do not have ffprobe you can use ffmpeg instead:

ffmpeg -i input.mkv -map 0:v:0 -c copy -f null -

• 这是一种快速的方法.
• 请参阅控制台输出结尾附近的frame=.
• 添加-discard nokey输入选项(在-i之前)以仅计算关键帧.
• This is a somewhat fast method.
• Refer to frame= near the end of the console output.
• Add the -discard nokey input option (before -i) to only count key frames.

使用-ignore_editlist 1输入选项忽略MP4/M4V/M4A/MOV编辑列表.默认值为不.忽略编辑列表.

Ignore the MP4/M4V/M4A/MOV edit list with the -ignore_editlist 1 input option. Default is to not ignore the edit list.

• -v error这将隐藏信息"输出(版本信息等)，这使解析变得更加容易.

• -v error This hides "info" output (version info, etc) which makes parsing easier.

-count_frames计算每个流的帧数，并在相应的流部分中报告.

-count_frames Count the number of frames per stream and report it in the corresponding stream section.

-select_streams v:0仅选择视频流.

-show_entries stream=nb_frames或-show_entries stream=nb_read_frames仅显示nb_frames或nb_read_frames的条目.

-of default=nokey=1:noprint_wrappers=1将输出格式(也称为书写器")设置为default，不要打印每个字段的键(nokey=1)，也不要打印节的页眉和页脚().还有更短的替代方法，例如-of csv=p=0.

-of default=nokey=1:noprint_wrappers=1 Set output format (aka the "writer") to default, do not print the key of each field (nokey=1), and do not print the section header and footer (noprint_wrappers=1). There are shorter alternatives such as -of csv=p=0.

• FFprobe文档
• FFmpeg Wiki:FFprobe提示
• FFprobe Documentation
• FFmpeg Wiki: FFprobe Tips

著名的mediainfo工具可以输出帧数:

The well known mediainfo tool can output the number of frames:

mediainfo --Output="Video;%FrameCount%" input.avi

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MP4Box

用于MP4/M4V/M4A文件.

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MP4Box

For MP4/M4V/M4A files.

MP4Box可以显示帧数:

MP4Box -info input.mp4

请参考相关视频流的输出中的Media Info行:

Refer to the Media Info line in the output for the video stream in question:

Media Info: Language "Undetermined (und)" - Type "vide:avc1" - 2525 samples

在此示例中，视频流具有2525帧.

In this example the video stream has 2525 frames.

用于MP4/M4V/M4A/MOV文件.

For MP4/M4V/M4A/MOV files.

boxdumper是l-smash的简单工具.它将输出大量信息.在stsz样本大小框部分下，请参考sample_count以获取帧数.在此示例中，输入具有1900个视频帧:

boxdumper is a simple tool from l-smash. It will output a large amount of information. Under the stsz sample size box section refer to sample_count for the number of frames. In this example the input has 1900 video frames:

boxdumper input.mp4
  ...
  [stsz: Sample Size Box]
    position = 342641
    size = 7620
    version = 0
    flags = 0x000000
    sample_size = 0 (variable)
    sample_count = 1900

• 请注意，一个文件可能包含多个stsz原子.
• Be aware that a file may have more than one stsz atom.

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