From 32260c405f801521149124ecd2948ddc242d6143 Mon Sep 17 00:00:00 2001 From: Andrew Weaver Date: Fri, 5 Jan 2018 09:26:10 -0800 Subject: [PATCH] Add stream md5s (#294) --- index.html | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/index.html b/index.html index 8355114..6710247 100644 --- a/index.html +++ b/index.html @@ -1672,6 +1672,28 @@ + + + +
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Create stream MD5s

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ffmpeg -i input_file -map 0:v:0 -c:v copy -f md5 output_file_1 -map 0:a:0 -c:a copy -f md5 output_file_2

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This will create MD5 checksums for the first video and the first audio stream in a file. If only one of these is necessary (for example if used on a WAV file) either part of the command can be excluded to create the desired MD5 only. Use of this kind of checksum enables integrity of the A/V information to be verified independently of any changes to surrounding metadata.

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ffmpeg
starts the command
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-i input_file
path, name and extension of the input file
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-map 0:v:0
selects the first video stream from the input
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-c:v copy
ensures that FFmpeg will not transcode the video to a different codec before generating the MD5
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output_file_1
is the output file for the video stream MD5. Example file extensions are .md5 and .txt
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-map 0:a:0
selects the first audio stream from the input
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-c:a copy
ensures that FFmpeg will not transcode the audio to a different codec before generating the MD5 (by default FFmpeg will use 16 bit PCM for audio MD5s).
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output_file_2
is the output file for the audio stream MD5.
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Note:The MD5s generated by running this command on WAV files are compatible with those embedded by the BWF MetaEdit tool and can be compared.

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