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• FFmpeg X264 multithread decoding

  16 novembre 2013, par Xin He

  I want to do H264 multithread decoding using FFmpeg. First I use X264 to encode yuv420 to file.x264 ./x264 -o file.x264 --slices 4 --input-res 1280x720 --fps 25 file_560x420.yuv

  The slices count is 4.

  However, when I use FFmpeg to decode, ./ffmpeg -y -threads 4 -thread_type slice -i file.x264 final.yuv

  FFmpeg calls func"execute_decode_slices" four times, not in a multithread way. I also found that in *execute_decode_slices(h, context_count)*, the context_count is 1. FFmpeg call this 4 times.

  Could someone help to solve this problem?

  Thanks very much!

• AndroidFFMPEG Appunite library issue

  16 novembre 2013, par Steve

  I am facing some with androidFfmpeg library on video seek.

  Can anyone help me out on this reported issue. jni_player_seek problem

• MP4's cutting out at the end when streaming FMS 3.5

  16 novembre 2013, par user1488848

  I am trying to stream a series of MP4's using FMS3.5 and some of the files seem to cut out a few seconds right before the end. I have used the ffmpeg bat proccess below, and when I increased the framerate to 500 it seems to have corrected itself although that has caused the files to be significantly larger. Was there anyway that I can keep the filesize and framerate lower while avoiding the cutout issue or some predefined settings I should be using when streaming MP4's off FMS 3.5

  ffmpeg -i input.mp4 -pass 1 -s 572x322 -vcodec libx264 -b 500k -flags +loop+mv4 \
  -cmp 256 -partitions +parti4x4+parti8x8+partp4x4+partp8x8+partb8x8 -me_method hex \
  -subq 7 -trellis 1 -refs 5 -bf 0 -flags2 +mixed_refs -coder 0 -me_range 16 \
  -g 250 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71 -qmin 10 -qmax 51 \
  -qdiff 4 -acodec libfaac -ab 160k -ac 1 output.mp4
  

• Avconv : Select german stream not highest quality one

  15 novembre 2013, par mblaettermann

  I am converting some input stream from my DVB S2 Card to RTMP.

  Everything works fine after switching to recent avconv and x264 :)

  The only thing I couldn't find out is, how do I select the right audio stream?

  The source sometimes has up to 6 audio tracks. Avconv automatically chooses the one with the highest bitrate. However I want to select the "ger" one:

  Here are the streams of ARTE german/french TV Channel for example:

  Input #0, mpegts, from 'http://192.168.1.50:9981/stream/channelid/1035':
    Duration: N/A, start: 19083.694722, bitrate: 15576 kb/s
    Program 1
      Stream #0.0[0xa8], 127, 1/90000: Video: mpeg2video (Main), yuv420p, 544x576 [PAR 32:17 DAR 16:9], 1/50, 15000 kb/s, 25 fps, 90k tb50 tbc
      Stream #0.1[0x70](fre), 204, 1/90000: Audio: mp2, 48000 Hz, stereo, s16p, 192 kb/s
      Stream #0.2[0x71](ger), 207, 1/90000: Audio: mp2, 48000 Hz, stereo, s16p, 128 kb/s
      Stream #0.3[0x72](eng), 207, 1/90000: Audio: mp2, 48000 Hz, stereo, s16p, 128 kb/s
      Stream #0.4[0x73](qaa), 207, 1/90000: Audio: mp2, 48000 Hz, stereo, s16p, 128 kb/s
    No Program
      Stream #0.5[0x3b], 126, 1/90000: Audio: mp1, 0 channels, s16p
  

  libav Docs are really not that helpful. Who does now the right syntax?

  EDIT: I found the -map option: http://ffmpeg.org/trac/ffmpeg/wiki/How%20to%20use%20-map%20option But it is not possible to map by name? Only by index?

  Maybe I need to use avprobe then, to find the corrent stream index for "ger".

• Video file with 2 audio streams, increase audio of first audio stream only [FFMPEG]

  15 novembre 2013, par BlasterGod

  Been fighting with this issue for quite some time, and I can't do anything to make it work. What I am doing is generating a video from images and adding 2 audio tracks to the video usign FFMPEG.

  Here is the command I use so far:

  ffmpeg  -i AUDIO1 -i AUDIO2 -fflags +genpts -r 1/5 -f image2  -i "c:\%%4d.jpg" -qscale:v 0K  -vcodec mjpeg -s 480x320  -y -r 30 -filter_complex amix=inputs=2,volume=1  "C:\asdasdasdasd3.avi" 
  

  I am using: -filter_complex amix=inputs=2,volume=1 to mix the 2 audio tracks and add them to the video. Before adding the audios to the video, I want to increase the volume of the first audio track (and leave the second audio file with the same volume).

  How can this be done?

  Thank you! Vlad