asheroto/ffmpeg-examples

Examples of common ffmpeg settings / arguments / parameters, especially for video conversion

Commonly recommended ffmpeg arguments for video conversion using x264

Feel free to contribute and send pull requests!

Recommended arguments for CPU conversion x264

Recommended arguments for NVIDIA GPUs x264

Recommended arguments for CPU conversion x265 or HEVC

mp4 format note

HLS format arguments (m3u8 + ts)

Stripping metadata

• Tweak the video bitrate and audio bitrate simply by changing the value of 2M or 192 Kbps to another appropriate value.
• If you are targeting 1080p type quality, 2M video and 192k audio is probably fine using 1920x1080 resolution.
• If you are targeting 720p type quality, 1M video and 192k audio is probably fine using 1280x720 resolution.

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Recommended arguments for CPU conversion x264

This will convert the source video to a 1080p, 30fps, 2Mbps video, 192 Kbps audio, output. It will strip the metadata, data streams, and subtitle streams.

Argument	Description
-i "input.mp4"	Source file
-c:v libx264	Encode the video using libx264 (CPU based)
-pix_fmt yuv420p	The 420p is misleading - this is just a standard pixel format
-filter:v fps=fps=30	Not a typo, filters the video for 30 fps
-b:v 2M	Set a bitrate of 2 Mbps for video
-b:a 192k	Set a bitrate of 192 Kbps for audio
-map_metadata -1	Strip metadata from source
-map 0:​v:0	Use the first video stream from the source
-map 0:​a:0	Use the first audio stream from the source
-map -0:d	Strip any data streams from the source
-map -0:s	Strip any subtitle streams from the source
-s 1920x1080	Set the resolution to 1920x1080 (1080p)
-c:a aac	Use aac format for audio (very standard)
-ac 2	Convert to stereo audio (in case from 5.1, etc, MUST use for HLS format)
-threads 6	Use 6 threads with ffmpeg
"output.mp4"	Destination file

ffmpeg -hwaccel cuda -i "input.mp4" -c:v h264_nvenc -pix_fmt yuv420p -filter:v fps=fps=30 -b:v 2M -b:a 192k -map_metadata -1 -map 0:v:0 -map 0:a:0 -map -0:d -map -0:s -s 1920x1080 -c:a aac -threads 6 "output.mp4"

Recommended arguments for NVIDIA GPUs x264

If you have an NVIDIA GPU, this is a faster way to encode vs the CPU

This will convert the source video to a 1080p, 30fps, 2Mbps video, 192 Kbps audio, output. It will strip the metadata, data streams, and subtitle streams.

Argument	Description
-hwaccel cuda	CUDA Hardware Acceleration (use if possible and no errors arise)
-i "input.mp4"	Source file
-c:v h264_nvenc	Encode the video using the NVIDIA NVENC encoder. Fast, great, but only if you have an NVIDIA graphics card)
-pix_fmt yuv420p	The 420p is misleading - this is just a standard pixel format
-filter:v fps=fps=30	Not a typo, filters the video for 30 fps
-b:v 2M	Set a bitrate of 2 Mbps for video
-b:a 192k	Set a bitrate of 192 Kbps for audio
-map_metadata -1	Strip metadata from source
-map 0:​v:0	Use the first video stream from the source
-map 0:​a:0	Use the first audio stream from the source
-map -0:d	Strip any data streams from the source
-map -0:s	Strip any subtitle streams from the source
-s 1920x1080	Set the resolution to 1920x1080 (1080p)
-c:a aac	Use aac format for audio (very standard)
-ac 2	Convert to stereo audio (in case from 5.1, etc, MUST use for HLS format)
-threads 6	Use 6 threads with ffmpeg
"output.mp4"	Destination file

ffmpeg -hwaccel cuda -i "input.mp4" -c:v h264_nvenc -pix_fmt yuv420p -filter:v fps=fps=30 -b:v 2M -b:a 192k -map_metadata -1 -map 0:v:0 -map 0:a:0 -map -0:d -map -0:s -s 1920x1080 -c:a aac -threads 6 "output.mp4"

Recommended arguments for CPU conversion x265 or HEVC

This will convert the source video using HEVC to a 1080p, 30fps, 2Mbps video, 192 Kbps audio, output. It will strip the metadata, data streams, and subtitle streams.

Note: You MUST use the 'essential' or 'full' build of ffmpeg. The default ffmpeg executable will NOT work with x265/HEVC. Download here.

At the current moment NVIDIA does not support a GPU-based encoder for x265/HEVC.

Argument	Description
-i "input.mp4"	Source file
-c:v libx265	Encode the video using libx265 (CPU based)
-pix_fmt yuv420p10le	Set x265 bit depth to 10-bit
-filter:v fps=fps=30	Not a typo, filters the video for 30 fps
-b:v 2M	Set a bitrate of 2 Mbps for video
-b:a 192k	Set a bitrate of 192 Kbps for audio
-map_metadata -1	Strip metadata from source
-map 0:​v:0	Use the first video stream from the source
-map 0:​a:0	Use the first audio stream from the source
-map -0:d	Strip any data streams from the source
-map -0:s	Strip any subtitle streams from the source
-s 1920x1080	Set the resolution to 1920x1080 (1080p)
-c:a aac	Use aac format for audio (very standard)
-ac 2	Convert to stereo audio (in case from 5.1, etc, MUST use for HLS format)
-threads 6	Use 6 threads with ffmpeg
"output.mp4"	Destination file

ffmpeg -i "input.mp4" -c:v libx265 -pix_fmt yuv420p10le -filter:v fps=fps=30 -b:v 2M -b:a 192k -map_metadata -1 -map 0:v:0 -map 0:a:0 -map -0:d -map -0:s -s 1920x1080 -c:a aac -threads 6 "output.mp4"

Variable bit rate

Instead of constraining the bitrate, you can have ffmpeg automatically decide based on a quality rating.

For x264, you can alternatively you can specify the following instead of using the -b:v 2M:

-rc vbr -cq 27 -qmin 27 -qmax 27 -b:v 0

Where 27 is good quality, good compression.

For x265/HEVC, you can alternatively you can specify the following instead of using the -b:v 2M:

-x265-params crf=26 -b:v 0

Where 26 is good quality, good compression.

Note: these numbers (26 vs 27) are on DIFFERENT scales and do DIFFERENT things See ffmpeg documentation

mp4 format note

Using the above examples, it will convert the source video to an mp4 file.

HLS format arguments

Argument	Description
-start_number 0	Start at ts number 0
-hls_time 10	Approx segment length (ts file)
-hls_list_size 0	Keep all segments in the playlist
-f hls	HLS format
"output.m3u8"	Output file (use m3u8 extension, it will create ts files)

Remove "output.mp4" from an above example and append this:

-start_number 0 -hls_time 10 -hls_list_size 0 -f hls "output.m3u8"

Stripping metadata

Additional arguments:

Argument	Description
-map_metadata -1	Don't copy metadata
-metadata encoder=""	Strip encoder metadata
-metadata handler_name=""	Strip handler_name metadata
-metadata title=""	Strip title metadata
-fflags +bitexact	Required to strip encoder metadata
-empty_hdlr_name 1	Required to set metadata to null in above args

Example:

-map_metadata -1 -metadata encoder="" -metadata handler_name="" -metadata title="" -fflags +bitexact -empty_hdlr_name 1

Full command if you just want to strip metadata and don't want to re-encode:

ffmpeg.exe -i "input.mp4" -map 0 -map_metadata -1 -metadata encoder="" -metadata handler_name="" -metadata title="" -fflags +bitexact -empty_hdlr_name 1 -c copy "output.mp4"

ffmpeg Documentation

See documentation here.