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• ffmpeg - how to "set" continuity counters when generating .ts segments for HLS live streaming ?

  17 mars 2021, par Rob

  Say I have a batch of 40 JPEGs that represent 2 FPS video, and I want to generate a m3u8 playlist + h264 ts segments for an HLS live stream - so I do something like this :

  



  ffmpeg -y -framerate 2 -start_number 0 -i /frames/frame_%d.jpg -frames:v 40 \
       -c:v libx264 -crf 21 -preset veryfast -g 2 \
       -f hls -hls_time 4 -hls_list_size 5 -hls_flags omit_endlist \
       -start_number 0 -segment_start_number 0 -segment_list_flags +live video/stream.m3u8


  



  and it gives me a playlist like this :

  



  #EXTM3U
#EXT-X-VERSION:3
#EXT-X-TARGETDURATION:4
#EXT-X-MEDIA-SEQUENCE:0
#EXTINF:4.000000,
stream0.ts
#EXTINF:4.000000,
stream1.ts
#EXTINF:4.000000,
stream2.ts
#EXTINF:4.000000,
stream3.ts
#EXTINF:4.000000,
stream4.ts


  



  Great. Now say I get another batch of 40 JPEGS that follows the first, and I want to drop stream0.ts (the first 4 seconds / 8 frames of the original 40 JPEGS), and add a new stream5.ts (the first 4 seconds / 8 frames of the next 40 JPEGS) :

  



  ffmpeg -y -framerate 2 -start_number 8 -i /frames/frame_%d.jpg -frames:v 40 \
       -c:v libx264 -crf 21 -preset veryfast -g 2 \
       -f hls -hls_time 4 -hls_list_size 5 -hls_flags omit_endlist \
       -start_number 1 -segment_start_number 1 -segment_list_flags live video/stream.m3u8


  



  Then I get this :

  



  #EXTM3U
#EXT-X-VERSION:3
#EXT-X-TARGETDURATION:4
#EXT-X-MEDIA-SEQUENCE:1
#EXTINF:4.000000,
stream1.ts
#EXTINF:4.000000,
stream2.ts
#EXTINF:4.000000,
stream3.ts
#EXTINF:4.000000,
stream4.ts
#EXTINF:4.000000,
stream5.ts


  



  Great. But when I try to play the HLS stream with something like HLS.js or video.js, my video stream stalls out. And when I inspect the stream with TSLemurs HLS Checker tool, it warns me about "CC" errors, which I assume means continuity counter errors :

  



  

  



  How can I fix these continuity counter errors ? Is there anyway to do this at all with ffmpeg ?

  


• Correct way for working with raw data when encoding using FFmpeg

  25 avril 2020, par midnightcoffee

  I am working on the android library for encoding/decoding raw data through ffmpeg. Every example I found uses files, it either reads or writes to a file. However, I am using raw byte array representing RGBA  image for encoder input and byte array for encoder output. Lets focus on encoding part for this question.

  



  My function looks like this : 

  



  int encodeRGBA(uint8_t *image, int imageSize, int presentationTimestamp,
 uint8_t *result, int resultSize)


  



  Where image is byte array containing raw rgba image data, imageSize is length of that array, presentationTimestamp is just counter used by AVFrame for setting pts, result is preallocated byte array with some defined length (currently with size matching width x height) and resultSize is byte array length (width x height). Returned int value represents actually used length of preallocated array. I am aware that this is not the best approach for sending data back to java and this is also part of the question. Is there a better way for returning result ?

  



  Example found here for encoding, directly writes byte data to the frame->data[0] (different approach for different formats, RGBA or YUV). But google search for "ffmpeg read from memory" results in examples like this, this or this. All of them suggesting using AVIOContext.

  



  I am confused how to use AVFormatContext with AVCodecContext for encoding ?

  



  Currently I have encoder working using first approach and I am successfully returning results as described (with preallocated byte array). I would like to know if that is wrong approach ? Should I be using AVIOContext for handling byte arrays ?

  


• i am getting when i am trying to run Ffmpegrabberframe on alpine image [closed]

  18 mars 2020, par avinash tiwari

  # # A fatal error has been detected by the Java Runtime Environment :

  # SIGSEGV (0xb) at pc=0x000000000000dc56, pid=446, tid=0x00007fd3c478db20 # # JRE version : OpenJDK Runtime Environment

  (8.0_242-b08) (build 1.8.0_242-b08) # Java VM : OpenJDK 64-Bit Server
  VM (25.242-b08 mixed mode linux-amd64 compressed oops) # Derivative :
  IcedTea 3.15.0 # Distribution : Custom build (Wed Jan 29 10:43:50 UTC
  2020) # Problematic frame : # C 0x000000000000dc56 # # Failed to
  write core dump. Core dumps have been disabled. To enable core
  dumping, try "ulimit -c unlimited" before starting Java again # # An
  error report file with more information is saved as : #
  /builds/had/tip/asset-delivery/firstgen-ingestion---backend/hs_err_pid446.log

  # If you would like to submit a bug report, please include # instructions on how to reproduce the bug and visit : #

  https://icedtea.classpath.org/bugzilla # Exception in thread
  "Thread-8" java.io.EOFException at
  java.io.ObjectInputStream$BlockDataInputStream.peekByte(ObjectInputStream.java:3015)
  at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1576)
  at java.io.ObjectInputStream.readObject(ObjectInputStream.java:465)
  at java.io.ObjectInputStream.readObject(ObjectInputStream.java:423)
  at
  org.scalatest.tools.Framework$ScalaTestRunner$Skeleton$1$React.react(Framework.scala:818)
  at
  org.scalatest.tools.Framework$ScalaTestRunner$Skeleton$1.run(Framework.scala:807)

  def extractAVI(rawDrivePath: String): List[String] = {
  
      var errorList: List[String] = List.empty
  
      FileUtils.listFiles(new File(rawDrivePath), new SuffixFileFilter(".avi"), TrueFileFilter.INSTANCE)
  
        .asScala.toList.foreach(aviFile => {
  
        var grabber: FFmpegFrameGrabber = null
  
        var aviStream: InputStream = null
  
        var isFailedExtraction: Boolean = false
  
        try {
  
          LOGGER.info(s"--------inside try----------${aviFile.getAbsolutePath}")
  
          aviStream = new FileInputStream(aviFile.getAbsolutePath)
  
          LOGGER.info("--------create grabber----------")
  
          grabber = new FFmpegFrameGrabber(aviStream)
  
          LOGGER.info("--------created grabber extraction of drives----------")
  
          grabber.start()
  
          LOGGER.info("--------start grabber of drives----------")
  
          var count: Int = 1
  
          for (frame <- Iterator.continually(grabber.grabImage()).takeWhile(_ != null)) {
  
            ImageIO.write(converter.convert(frame), "jpg", new File(aviFile.getParent, "capture-" + count + ".jpg"))
  
            count += 1
  
          }
  
          grabber.stop()
  
        } catch {
  
          case ex: Exception => {
  
            LOGGER.info(s"Error while extracting images for ${aviFile.getAbsolutePath} {}", ex)
  
            errorList :+= s"${aviFile.getAbsolutePath.replace(rawDrivePath, "")} -> ${ex.getMessage}"
  
            isFailedExtraction = true
  
            LOGGER.info("last inside catch")
  
          }
  
        } finally {
  
          // Close the video file
  
          LOGGER.info(s"inside finally ")
  
          if (grabber != null)
  
            grabber.release()
  
          if (aviStream != null)
  
            aviStream.close()
  
          if (aviFile.exists() && !isFailedExtraction) {
  
            LOGGER.debug(s"Deleting ${aviFile.getAbsolutePath}")
  
            FileUtils.deleteQuietly(aviFile)
  
          }
  
        }
  
      })