How to use the command ffplay (with examples)

FFplay is a simple and portable media player that utilizes the FFmpeg libraries and the SDL library. It allows users to play media files, both audio and video, with various options and features.

Use case 1: Play a media file

Code:

ffplay path/to/file

Motivation: This use case allows you to play a media file using ffplay. It can be useful when you want to quickly preview the content of a file without opening a full-fledged media player.

Explanation: The command begins with “ffplay” followed by the path to the media file you want to play. This command will launch ffplay and start playing the media file in a separate player window.

Example output: The media file specified will open in a player window, and the content will start playing.

Use case 2: Play audio from a media file without a GUI

Code:

ffplay -nodisp path/to/file

Motivation: This use case is helpful when you only want to listen to the audio of a media file without displaying the video content. It can be useful when you are working on tasks that require audio analysis or when you have limited resources.

Explanation: By adding the “-nodisp” option before specifying the path to the media file, ffplay will run without displaying the video content, allowing you to focus solely on the audio.

Example output: The audio from the specified media file will start playing, while no video output is displayed.

Use case 3: Play media passed by ffmpeg through stdin

Code:

ffmpeg -i path/to/file -c copy -f media_format - | ffplay -

Motivation: This use case is valuable when you’re working with ffmpeg and want to play media directly from the output of ffmpeg rather than saving it to a file first. It offers more flexibility in media processing and streaming.

Explanation: In this command, “ffmpeg -i path/to/file -c copy -f media_format -” is used to read a media file, process it, and pass it through stdin. The “|” symbol is a pipe that directs the output from ffmpeg to the input of ffplay. The “-” at the end indicates that ffplay should read from stdin.

Example output: The media file specified will be processed by ffmpeg and passed to ffplay, which will display and play the content in its player window.

Use case 4: Play a video and show motion vectors in real time

Code:

ffplay -flags2 +export_mvs -vf codecview=mv=pf+bf+bb path/to/file

Motivation: This use case is helpful when you want to analyze the motion vectors of a video in real time. It can be useful for debugging purposes or to gain insights into the motion of objects within a video.

Explanation: The “-flags2 +export_mvs” option enables the export of motion vectors. The “-vf codecview=mv=pf+bf+bb” option sets up the filtergraph to show motion vectors. The path to the video file is then provided as an argument.

Example output: The video will play, and the player window will display the motion vectors overlaid on top of the video frames in real time.

Use case 5: Show only video keyframes

Code:

ffplay -vf select="eq(pict_type\,PICT_TYPE_I)" path/to/file

Motivation: This use case can be useful when you want to analyze only the video keyframes without the intermediate frames. It allows you to focus on the most critical frames in video analysis or when you need to examine specific moments in a video.

Explanation: The “-vf select=“eq(pict_type,PICT_TYPE_I)” option sets up a filtergraph that selects only the video keyframes. The path to the video file is then provided as an argument.

Example output: The player window will display only the keyframes of the video specified, skipping the intermediate frames.

Conclusion:

In conclusion, ffplay is a versatile media player that offers various features and options for playing media files. Whether you need to quickly preview a file, analyze the audio, process streamed media, examine motion vectors, or focus on video keyframes, ffplay provides the necessary functionality. By understanding these use cases and their corresponding commands, you can make the most out of this powerful media player.