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• Encoding video for real time streaming

  15 septembre 2019, par lilroo

  Miguel Grinberg’s article video streaming with flask, covers sending multiple JPG formatted images to a client through a multipart response to stream video to the browser.

  After doing some reading, I quickly realized that MJPEG is not a real video format, JPEGs are not optimized for video streaming and MJPEG cannot be streamed to a HTML5 video element.

  for my application (a screen sharing application written in python), I need to be able to encode and stream relatively smooth video (smoother than MJPEG anyway) in semi-realtime to the browser.

  I think what I need to do is encode a video stream using a tool like FFmpeg and then send chunks of that output to a browser using a multipart response - however it doesn’t look like there is a way to get FFmpeg (using python bindings) to write to an in-memory buffer.

  Is ffmpeg up to this task ?

  I appreciate that this question may sound nieve, but I would be thankful for being pointed in the right direction.

• Extract frames as images from an RTMP stream in real-time

  7 novembre 2014, par SoftForge

  I am streaming short videos (4 or 5 seconds) encoded in H264 at 15 fps in VGA quality from different clients to a server using RTMP which produced an FLV file. I need to analyse the frames from the video as images as soon as possible so I need the frames to be written as PNG images as they are received.

  Currently I use Wowza to receive the streams and I have tried using the transcoder API to access the individual frames and write them to PNGs. This partially works but there is about a second delay before the transcoder starts processing and when the stream ends Wowza flushes its buffers causing the last second not to get transcoded meaning I can lose the last 25% of the video frames. I have tried to find a workaround but Wowza say that it is not possible to prevent the buffer getting flushed. It is also not the ideal solution because there is a 1 second delay before I start getting frames and I have to re-encode the video when using the transcoder which is computationally expensive and unnecessarily for my needs.

  I have also tried piping a video in real-time to FFmpeg and getting it to produce the PNG images but unfortunately it waits until it receives the entire video before producing the PNG frames.

  How can I extract all of the frames from the stream as close to real-time as possible ? I don’t mind what language or technology is used as long as it can run on a Linux server. I would be happy to use FFmpeg if I can find a way to get it to write the images while it is still receiving the video or even Wowza if I can find a way not to lose frames and not to re-encode.

  Thanks for any help or suggestions.

• fftools/ffmpeg_filter : keep track of the real filter input type

  13 mai 2023, par Anton Khirnov

  fftools/ffmpeg_filter : keep track of the real filter input type
  Avoid extracting it from various remote sources.
  

  • [DH] fftools/ffmpeg_filter.c