[FFmpeg-trac] #2101(undetermined:new): Please document -i foo%d.jpg correctly

FFmpeg trac at avcodec.org
Wed Jan 2 22:11:14 CET 2013


#2101: Please document -i foo%d.jpg correctly
-------------------------------------+-------------------------------------
             Reporter:               |                     Type:  defect
  norman_hendrich                    |                 Priority:  normal
               Status:  new          |                  Version:
            Component:               |  unspecified
  undetermined                       |               Blocked By:
             Keywords:               |  Reproduced by developer:  0
  Documentation incomplete           |
             Blocking:               |
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Hi guys,

 I just wasted a couple of hours of my life reading broken
 ffmpeg documentation. A friend sent me a nice script
 to create a time-lapse video from existing JPEGs using
 ffmpeg, but it didn't work.

 Documentation was a complete disaster, and error-messages
 misleading. Debugging with strace finally showed what the
 stupid thing was doing. Adding one line of documentation
 will fix this.



 Summary of the bug:
 How to reproduce:

 What my friend sent me:

 ffmpeg -f image2 -r 60 -i mod_image%d.jpg -r 60 -vcodec libx264 video.mp4

 What I have:
 Ubuntu 12.04 LTS with most recent upstream ffmpeg (0.8 something).

 trial-005-camera0.jpg
 trial-006-camera0.jpg
 trial-007-camera0.jpg
 ...

 this didn't work out-of-the-box. You may already suspect, why.

 BUG 1:
 What the online docs document: -pattern_type glob ...
 This does NOT work on Ubuntu 12.04LTS. The option may have been added
 later, but it is not on the actual install. Online docs might mention
 that this option has only been added recently (if it is indeed working
 somewhere. I have my doubts this option will handle the start-index
 bug mentioned below).


 BUG 2:
 This particular ffmpeg version tells me that it is outdated,
 and I should run avconv instead. No need to tell you, avconv
 has the same options documented, but doesn't work on 12.04 either.



 BUG 3:
 I finally understood that foo-%d-bar.jpg was not supported.
 Renaming all my files to the foo-%d.jpg pattern was easy.

 Running the above script (with "-i mod_image%d.jpg") still tells
 me "No such file". Strace shows it checks 000 .. 004 and then gives
 up. This is highly non-transparent to the unsuspecting user.

 Please DOCUMENT that your s/f...../fine program REQUIRES the image
 numbering
 to start with 0..4, or it will give up. Needless to say, my images
 started with 005. That would add only one line in the online docs.

 Another idea would be to have a "start index" option.

 Probably affects all versions.

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2101>
FFmpeg <http://ffmpeg.org>
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