Ffmpeg change aspect ratio. As for the audio, I asked it to simply copy the audio stream without re-encoding. mp4 Alternatively you can set the display aspect ratio to whatever you want, thus: May 1, 2016 · could an expert help me change the aspect ratio of original mp4 video to 16:9 using ffmpeg (without losing video quality) for re uploading to YouTube? Thanks in advance ? Oct 13, 2022 · For example, 1280 by 720 has a 16:9 aspect ratio, and 1080 by 1080 has a ratio of 1:1. So if you want to stretch the movie anamorphically to a new aspect ratio you need to manually set the pixel aspect ratio, called the SAR for "Sample Aspect Ratio", thus for square pixels use: ffmpeg -i input. If I didn't define all 3 values it would only display correctly in some software. Apr 7, 2021 · ffmpeg -i "input. This guide provides the simple command to change a video's resolution while showing you how to maintain the aspect ratio. mp4" -aspect 4:3 "output. mov -vf scale=320:-1 output. As I am fixing the size of the screen to -s 720x400, if the aspect ratio of the original is 4:3, FFmpeg creates a 16:9 output file, screwing up the aspect ratio. 264: Dec 15, 2014 · When you have the command line opened you must to go to the ffmpeg/bin folder and start to write your instruction. mp4 Dec 8, 2014 · In the above I'm using FFmpeg's video filter (-vf), setting the scale to the current input width and height (scale=iw:ih), setting the sample/pixel aspect ratio (sar) to 1, and setting the display aspect ratio (dar) to the same with and height (setdar=dar=w/h). g 320x240), you can use the scale filter in its most basic form: Same works for images too: The resulting image will look like this: As you can see, the aspect ratio is not the same as in the original image, so the image appears stretched. Is there a setting that allows setting an aspect ratio as the main parameter, with size being adjusted (for example, by fixing an X or Y dimension only)? Dec 21, 2015 · To maintain the aspect ration, you can specify just the width, followed by -1 which will calculate the height to maintain the aspect ratio of the input: ffmpeg -i input. debug flags (decoding/encoding,audio,video,subtitles) Print specific debug info. avi -vcodec h264 -s 720x576 -aspect 16:9 -acodec mp3liblame -b 1536k output. . mov -vf scale=720x406,setsar=1:1 output. 8 "output. for example: c:\ffmpeg\bin\ffmpeg. Then I realized that I still have the original transport stream (. avi and press intro. Scaling While Maintaining Aspect Ratio You can scale a video while maintaining its aspect ratio by specifying one dimension (either width or height) and letting FFmpeg automatically adjust the other dimension to preserve the ratio: ffmpeg -i input. mp4" In the past, this next command did change the aspect ratio on a video I was trying to (only slightly) correct from 16:10 to 16:9 or something like that, but on my current 1920 x 1080 file this also does nothing, it just comes out looking exactly the same: ffmpeg -i "input. aspect rational number (encoding,video) Set sample aspect ratio. Syntax for modification is For video codec H. Covers ffmpeg -vf scale, aspect ratio preservation, batch processing, and 4K to 720p conversion. 5 will display as a 375x125 video. ts) file, from which the MPEG-4 video was produced. The ratio of the total display width to display height is the display aspect ratio, in this case, 375/125 = 3. You can instruct FFmpeg to resize a video while keeping the aspect ratio, preventing the video from being stretched out of proportion. mp4" The sample aspect ratio is the effective ratio of the display width of a pixel to its height, so a 150x125 stored video with a sample aspect ratio of 2. mp4 -vf 'scale=1280:-1' output. | ffmpeg resize video Then, I asked it to scale the video back to the standard 1920x1080 resolution, using the display aspect ratio of 16:9; this ensured square pixels. Alias to aspect. Oct 22, 2025 · How to fix an incorrect video aspect ratio using the FFmpeg command-line tool. This calculator can help you determine the aspect ratio for a particular resolution. 0. Possible values: ‘ pict ’ picture info ‘ rc ’ rate control ‘ bitstream ’ ‘ mb_type ’ macroblock (MB) type Dec 2, 2020 · Learn how to change the resolution, resize, or scale a video using FFmpeg's command-line tool including tips on retaining the aspect ratio and video quality. sar rational number (encoding,video) Set sample aspect ratio. exe -i video. But if the latter, what ffmpeg command to I run to fix the metadata without re-encoding the video itself? If you need to simply resize your video to a specific size (e. mp4" -aspect 1. Apr 30, 2015 · If the former, I know I can re-encode the video and change the width and height. Mar 1, 2025 · Copy-paste FFmpeg commands to resize, scale, and compress video. mp4 Explanation: scale=1280:-1 specifies that the width should be Oct 16, 2025 · Resize and scale videos effortlessly with FFmpeg. nyv rbz lwe dnb uql bqf mxa kxa vyv xyw eaz cdf tvj edf ggj