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• Cannot install ffmpeg via brew on macOS Mojave

  12 juillet 2018, par Savinggrace
  • Xcode 10 beta installed
  • Command line tool for macOS 10.14 installed
  • macOS_SDK_headers_for_macOS_10.14.pkg installed
  • brew update done ;

  When trying to install ffmpeg by brew install ffmpeg, I had un error below :

  tar: Error exit delayed from previous errors.
  
  Error: Failure while executing: tar xf /Users/myname/Library/Caches/Homebrew/texi2html-5.0.tar.gz -C /private/tmp/texi2html-20180712-39689-hmsh90

  Which seems like a problem of Homebrew texi2html-5.0.tar.gz.

  Then using brew info ffmpeg :

  ffmpeg: stable 4.0.1, HEAD
  
  Play, record, convert, and stream audio and video
  
  https://ffmpeg.org/
  
  Not installed
  
  From: https://github.com/Homebrew/homebrew-core/blob/master/Formula/ffmpeg.rb
  
  ==> Dependencies
  
  Build: nasm ✔, pkg-config ✔, texi2html ✘
  
  Recommended: lame ✘, x264 ✘, xvid ✘
  
  Optional: chromaprint ✘, fdk-aac ✘, fontconfig ✘, freetype ✘, frei0r ✘, game-music-emu ✘, libass ✘, libbluray ✘, libbs2b ✘, libcaca ✘, libgsm ✘, libmodplug ✘, librsvg ✘, libsoxr ✘, libssh ✘, libvidstab ✘, libvorbis ✘, libvpx ✘, opencore-amr ✘, openh264 ✘, openjpeg ✘, openssl ✘, opus ✘, rtmpdump ✘, rubberband ✘, sdl2 ✘, snappy ✘, speex ✘, tesseract ✘, theora ✘, two-lame ✘, wavpack ✘, webp ✘, x265 ✘, xz ✔, zeromq ✘, zimg ✘, srt ✘

  As is not working, so I just downloaded static FFmpeg binaries for macOS 64-bit from https://evermeet.cx/ffmpeg/ and moved the exec file to /usr/local/bin/ and now ffmpeg works perfectly.

  But I’m still curious to know how to resolve this brew error.

  Thanks in advance if anyone has the solution.

• ffmpeg same bit rate in hls file

  2 août 2019, par Saurabh

  We are using following command to generate dash and hls file for a given video :

  ffmpeg -y -nostdin -loglevel error -i input.mp4 \
  
          -map 0:v:0  -map 0:v:0 -map 0:v:0  -map 0:v:0  -map 0:v:0  -map 0:v:0 -map 0:a\?:0  \
  
          -maxrate:v:0 350k -bufsize:v:0 700k  -c:v:0 libx264 -filter:v:0 "scale=320:-2"  \
  
          -maxrate:v:1 1000k -bufsize:v:0 2000k -c:v:1 libx264 -filter:v:1 "scale=640:-2"  \
  
          -maxrate:v:2 3000k -bufsize:v:0 6000k -c:v:2 libx264 -filter:v:2 "scale=1280:-2" \
  
          -maxrate:v:3 245k -bufsize:v:3 600k -c:v:3 libvpx-vp9 -filter:v:3 "scale=320:-2"  \
  
          -maxrate:v:4 700k  -bufsize:v:3 1400k -c:v:4 libvpx-vp9 -filter:v:4 "scale=640:-2"  \
  
          -maxrate:v:5 2100k -bufsize:v:3 4200k -c:v:5 libvpx-vp9 -filter:v:5 "scale=1280:-2"  \
  
          -use_timeline 1 -use_template 1 -adaptation_sets "id=0,streams=v  id=1,streams=a" \
  
          -threads 8 -seg_duration 5 -hls_playlist true -f dash output/output.mpd

  This works and generates hls files also as expected, one sample m3u8 file below :

  #EXTM3U
  
  #EXT-X-VERSION:7
  
  #EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="group_A1",NAME="audio_6",DEFAULT=YES,URI="media_6.m3u8"
  
  #EXT-X-STREAM-INF:BANDWIDTH=129663,RESOLUTION=320x168,CODECS="avc1.64000c,mp4a.40.2",AUDIO="group_A1"
  
  media_0.m3u8
  
  
  
  #EXT-X-STREAM-INF:BANDWIDTH=129663,RESOLUTION=640x336,CODECS="avc1.64001e,mp4a.40.2",AUDIO="group_A1"
  
  media_1.m3u8
  
  
  
  #EXT-X-STREAM-INF:BANDWIDTH=129663,RESOLUTION=1280x670,CODECS="avc1.64001f,mp4a.40.2",AUDIO="group_A1"
  
  media_2.m3u8
  
  
  
  #EXT-X-STREAM-INF:BANDWIDTH=330756,RESOLUTION=320x168,CODECS="vp09.00.11.08,mp4a.40.2",AUDIO="group_A1"
  
  media_3.m3u8
  
  
  
  #EXT-X-STREAM-INF:BANDWIDTH=329663,RESOLUTION=640x336,CODECS="vp09.00.21.08,mp4a.40.2",AUDIO="group_A1"
  
  media_4.m3u8
  
  
  
  #EXT-X-STREAM-INF:BANDWIDTH=329663,RESOLUTION=1280x670,CODECS="vp09.00.31.08,mp4a.40.2",AUDIO="group_A1"
  
  media_5.m3u8

  Now as you notice, the Bandwidth is same for resolution of 320x168, 640x336 and 1280x670, which might have happened because of nature of video.

  But the issue with this is in iOS’s AVPlayer it always picks the minimum resolution one and never picks the better resolution stream even if it is available because of same bitrate.

  So the question I want to ask is : is there some option available to ensure - I always have some difference in the bitrates of different resolutions or more specific, bit rate always increase(may be just by few bytes) for increasing resolutions.

• Saving a continuous stream of images from ffmpeg image2pipe using golang

  11 février 2020, par Mina

  I am trying to save a sequence/continuous images from ffmpeg image2pipe in go. The problem with the code below that it does only save the first image in the stream due to the blocking nature of io.Copy since it waits for the reader or the writer to close.

  package main
  
  
  
  import (
  
      "fmt"
  
      "io"
  
      "log"
  
      "os"
  
      "os/exec"
  
      "strconv"
  
      "time"
  
  )
  
  
  
  //Trying to get png from stdout pipe
  
  
  
  func main() {
  
      fmt.Println("Running the camera stream")
  
      ffmpegCmd := exec.Command("ffmpeg", "-loglevel", "quiet", "-y", "-rtsp_transport", "tcp", "-i", "rtsp://admin:123456@192.168.1.41:554/h264Preview_01_main", "-r", "1", "-f", "image2pipe", "pipe:1")
  
  
  
      ffmpegOut, err := ffmpegCmd.StdoutPipe()
  
      if err != nil {
  
          return
  
      }
  
  
  
      err = ffmpegCmd.Start()
  
  
  
      if err != nil {
  
          log.Fatal(err)
  
      }
  
  
  
      count := 0
  
      for {
  
          count++
  
          t := time.Now()
  
          fmt.Println("writing image" + strconv.Itoa(count))
  
          filepath := "image-" + strconv.Itoa(count) + "-" + t.Format("20060102150405.png")
  
  
  
          out, err := os.Create(filepath)
  
          if err != nil {
  
              log.Fatal(err)
  
          }
  
          defer out.Close()
  
  
  
          _, err = io.Copy(out, ffmpegOut)
  
          if err != nil {
  
              log.Fatalf("unable to copy to file: %s", err.Error())
  
          }
  
      }
  
      if err := ffmpegCmd.Wait(); err != nil {
  
          log.Fatal("Error while waiting:", err)
  
      }
  
  }

  I implemented my own save and copy function based on the io.Copy code https://golang.org/src/io/io.go

  func copyAndSave(w io.Writer, r io.Reader) error {
  
      buf := make([]byte, 1024, 1024)
  
      for {
  
          n, err := r.Read(buf[:])
  
          if n == 0 {
  
  
  
          }
  
          if n > 0 {
  
              d := buf[:n]
  
              _, err := w.Write(d)
  
              if err != nil {
  
                  return err
  
              }
  
          }
  
          if err != nil {
  
              return err
  
          }
  
  
  
      }
  
      return nil
  
  }

  then I updated the for loop in my main function to the below block but still I am only getting the first image in the sequence. due to r.Read(buf[:]) is being a blocking call.

  for {
  
          count++
  
          t := time.Now()
  
          fmt.Println("writing image" + strconv.Itoa(count))
  
          filepath := "image-" + strconv.Itoa(count) + "-" + t.Format("20060102150405.png")
  
  
  
          out, err := os.Create(filepath)
  
          if err != nil {
  
              log.Fatal(err)
  
          }
  
          defer out.Close()
  
  
  
          err = copyAndSave(out, ffmpegOut)
  
          if err != nil {
  
              if err == io.EOF {
  
                  break
  
              }
  
              log.Fatalf("unable to copy to file: %s", err.Error())
  
              break
  
          }
  
      }

  Any help is appreciated and sorry for in typos in advance :)