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• h264 Licensing, ffmpeg iPhone transcoding

  28 février 2013, par NadavRub

  Requirements
  
  1. An application that should run, to begin with, on iPhone, and, in the end on a plurality
   of SmartPhone devices.
  2. Aim at having the trans-coding code supporting as much OSs as possible.
  3. Application is commercial.

  Use-case
  
  I. Record video using the portable SmartPhone Camera application
  II. Trans-code the video into a plurality of bit-rates using a cutom app
  

  iPhone Implementation
  
  A. To satisfy requirement [2], Implement Trans-coding using C++
  B. Use ffmpeg for trans-coding.
  

  Problem
  - Using ffmpeg to encode H264 req usage of the x264 lib
  - H264 encoding mandate payment for Licensing.

  In order to avoid H264 Licensing
  - The iPhone device ( and many others ) come with built-in H264 encoding capability
  - Usage of the built-in H264 Codec will avoid licensing problems/restrictions
  

  ---

  Does ffmpeg, supports, in any way, usage of iPhone's built-in H264 encoder ?
  
  
  
  Any help will be appreciated.

• Can iPhone stream radio with ffmpeg library ?

  2 avril 2012, par cnu

  Sorry if it's dumb question

  Can ffmpeg library for iPhone convert streaming radio sources for desires format say mp3 ?

  Or can you suggest any other library please

• How to record a livestream in ffmpeg or gstreamer and split the files without skipping or duplicating frames

  15 décembre 2020, par Blake Cochrane

  Can somone please recommend a solution for safely recording a live stream to a file that would not produce a corrupted file if the system was unsavely shut down.

  


  I am starting on a project using a battery powered Raspberry Pi 4B.
I am using GStreamer to use the ASIC for Raw Pi camera to h.264 compression to create a RTSP/HLS/RTMP stream.
I need to continuosly record the livestream to a file on the Pi without any duplicate & missing frames or transcoding - eg using -vcodec copy.
As the Pi is battery powered, it can be unsafely shut down randomly when the battery is out of energy.
I know that if a mp4 container isn't 'finalised' with the moov atom before the file finishes writing which would leave the file corrupted/unrepairable and unplayable.
So if I have an mp4 recording of 6 hours that is corrupted and unfixable that is a problem.
My idea was to split the recording to a new file after x amount of minutes or frames or bytes as losing the last few minutes is not so bad as to lose hours of recordings.
I would need to set the last frame in the old file as the previous frame to the next I frame (starting frame) in the new file as a h.264 stream can only start on an I frame.

  


  So it would go like this.
file 1
| Frame |0001|I|
| --- | --- | --- |
|Frame|0002|P|
|Frame|0003|B|
...
| Frame |1524|B|
| --- | --- | --- |
| Frame |1525|P|

  


  file 2
| Frame |1526|I|
| --- | --- | --- |
| Frame |1527|B|

  


  Then all of the split files can be appended to each other without transcoding in ffmpeg.
I don't need to record the live stream directly to an mp4, whatever container it is in can be converted to an mp4 when appending the split files.

  


  There is a python script of the Raspberry pi that accomplishes all of this but it can not be used for a live stream multicast as the Pi camera can not be accessed by more than one process at a time.
Unless there is a way to live stream the latest frames in an mp4 file that is continiously being recorded to, I am stuck.