Short Notes on ffmpeg - Revision history

Admin at 08:00, 2 September 2019

2019-09-02T08:00:11Z

Admin: /* Rip DVD into FLV (or anything else) */

2013-10-28T11:34:38Z

‎Rip DVD into FLV (or anything else)

Admin: Created page with "The `ffmpeg` is probably the most versatile encoder/transcoder for video and audio. It supports every format there is, and some of those that do not exist ;-). == Rip DVD..."

2012-06-01T21:51:08Z

Created page with "The <tt>ffmpeg</tt> is probably the most versatile encoder/transcoder for video and audio. It supports every format there is, and some of those that do not exist ;-). == Rip DVD..."

New page

The <tt>ffmpeg</tt> is probably the most versatile encoder/transcoder for video and audio. It supports every format there is, and some of those that do not exist ;-).

== Rip DVD into FLV (or anything else) ==

This is trivial, just few parameters need tweaking, and is you wanna use mp3 for your FLV, you either wanna compile <tt>ffmpeg</tt> by hand, or - in Ubuntu - install extras for libavcodec - <tt>libavcoded-extra-53</tt> in 11.10, and <tt>libavcoded-extra-52</tt> in 11.04.

Of course, you may use any ''vcodec'' and ''acodec'' you want.

Then, all you have to do is:
<pre>cat /media/mydisk/VIDEO_TS/VTS_01_[1234].VOB | \
ffmpeg -i - -s 640x480 -deinterlace -vcodec flv -acodec libmp3lame -vb 1500k -ab 128k -ar 44100 ~/output.flv</pre>

← Older revision		Revision as of 08:00, 2 September 2019
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	The important switch in the above command is the <tt>-shortest</tt>, that tells ffmpeg to stop encoding when "shorter" track ends, in this case the audio track; since input image is loop'ed, the encoding would go on forever otherwise.		The important switch in the above command is the <tt>-shortest</tt>, that tells ffmpeg to stop encoding when "shorter" track ends, in this case the audio track; since input image is loop'ed, the encoding would go on forever otherwise.
		+
		+	== Concatenate Videos ==
		+
		+	=== Same Size and All... ===
		+
		+	This is, fortunately, trivial.
		+
		+	If all files on the input are same resolution, frame rate, etc., e.g. segments of captured stream, create a file <code>segments.txt</code> with the list of filenames:
		+
		+	<pre>file 'segment1.mp4'
		+	file 'segment2.mp4'
		+	# ...
		+	file 'segment73.mp4'</pre>
		+
		+	This list is then fed to the <code>concat</code> filter:
		+
		+	<pre>ffmpeg -f concat -safe 0 -i segments.txt -c copy output.mp4</pre>
		+
		+	=== Requiring Re-encoding ===
		+
		+	Gets a bit more messy, but not too messy :)
		+
		+	You needs to instruct <code>ffmpeg</code> to map each file's stream, and then map those together into the output file.
		+
		+	Example with 2 files:
		+
		+	<pre>ffmpeg -i input1.mp4 -i input2.webm \
		+	-filter_complex "[0:v:0][0:a:0][1:v:0][1:a:0]concat=n=2:v=1:a=1[outv][outa]" \
		+	-map "[outv]" -map "[outa]" output.mp4</pre>
		+
		+	General syntax with <code>N</code> files:
		+
		+	<pre>ffmpeg -i file1.ext ... -i fileN.ext \
		+	-filter_complex "[0:v:0][0:a:0]...[N:v:0][N:a:0]concat=n=N:v=1:a=1[outv][outa]" \
		+	-map "[outv]" -map "[outa]" output.ext</pre>
		+
		+	Of course, you can add all additional parameters to each input and output file (skip/trim, resolution, ...).
		+
		+	[https://trac.ffmpeg.org/wiki/Concatenate see much more at ffmpeg docs]

← Older revision		Revision as of 11:34, 28 October 2013
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	<pre>cat /media/mydisk/VIDEO_TS/VTS_01_[1234].VOB \| \		<pre>cat /media/mydisk/VIDEO_TS/VTS_01_[1234].VOB \| \
	ffmpeg -i - -s 640x480 -deinterlace -vcodec flv -acodec libmp3lame -vb 1500k -ab 128k -ar 44100 ~/output.flv</pre>		ffmpeg -i - -s 640x480 -deinterlace -vcodec flv -acodec libmp3lame -vb 1500k -ab 128k -ar 44100 ~/output.flv</pre>
		+
		+	== Still Image with Audio ==
		+
		+	To upload sound track to YouTube, you need to provide video file, not just audio.
		+
		+	With ffmpeg it's simple to create video with still image and audio track:
		+
		+	<pre>ffmpeg -loop 1 -i still-image.jpg -i audio-track.mp3 -vcodec libxvid -acodec libmp3lame -ab 128k -shortest video.avi</pre>
		+
		+	The important switch in the above command is the <tt>-shortest</tt>, that tells ffmpeg to stop encoding when "shorter" track ends, in this case the audio track; since input image is loop'ed, the encoding would go on forever otherwise.

Short Notes on ffmpeg - Revision history

Admin at 08:00, 2 September 2019

Admin: /* Rip DVD into FLV (or anything else) */

Admin: Created page with "The ffmpeg is probably the most versatile encoder/transcoder for video and audio. It supports every format there is, and some of those that do not exist ;-). == Rip DVD..."

Admin: Created page with "The `ffmpeg` is probably the most versatile encoder/transcoder for video and audio. It supports every format there is, and some of those that do not exist ;-). == Rip DVD..."