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  • understanding libx264 output [closed]

    11 août 2015, par nmxprime

    I used libx264 in ffmpeg to encode . Finally i got below output .

    Can anyone guide me understanding & interpreting this?? Any reference/documentation?

    01-01 06:34:43.650: I/stderr(6603): [libx264 @ 0xdd2040] frame I:7     Avg QP:27.51  size: 11996
01-01 06:34:43.650: I/stderr(6603): [libx264 @ 0xdd2040] frame P:32    Avg QP:26.90  size:   217
01-01 06:34:43.650: I/stderr(6603): [libx264 @ 0xdd2040] frame B:25    Avg QP:32.73  size:    39
01-01 06:34:43.650: I/stderr(6603): [libx264 @ 0xdd2040] consecutive B-frames: 20.0% 80.0%
01-01 06:34:43.650: I/stderr(6603): [libx264 @ 0xdd2040] mb I  I16..4: 74.1% 17.0%  8.9%
01-01 06:34:43.650: I/stderr(6603): [libx264 @ 0xdd2040] mb P  I16..4:  0.7%  0.1%  0.0%  P16..4:  2.0%  0.3%  0.2%  0.0%  0.0%    skip:96.6%
01-01 06:34:43.650: I/stderr(6603): [libx264 @ 0xdd2040] mb B  I16..4:  0.0%  0.0%  0.0%  B16..8:  1.2%  0.0%  0.0%  direct: 0.1%  skip:98.8%  L0: 5.5% L1:94.5% BI: 0.0%
01-01 06:34:43.650: I/stderr(6603): [libx264 @ 0xdd2040] final ratefactor: 22.43
01-01 06:34:43.650: I/stderr(6603): [libx264 @ 0xdd2040] 8x8 transform intra:16.9% inter:51.1%
01-01 06:34:43.650: I/stderr(6603): [libx264 @ 0xdd2040] coded y,uvDC,uvAC intra: 12.8% 27.2% 24.4% inter: 0.3% 0.6% 0.0%
01-01 06:34:43.650: I/stderr(6603): [libx264 @ 0xdd2040] i16 v,h,dc,p: 95%  5%  0%  0%
01-01 06:34:43.650: I/stderr(6603): [libx264 @ 0xdd2040] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu:  2% 30% 60%  0%  1%  0%  2%  0%  4%
01-01 06:34:43.650: I/stderr(6603): [libx264 @ 0xdd2040] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu:  7% 58% 10%  2%  4%  2%  9%  1%  8%
01-01 06:34:43.650: I/stderr(6603): [libx264 @ 0xdd2040] i8c dc,h,v,p: 14% 81%  3%  3%
01-01 06:34:43.650: I/stderr(6603): [libx264 @ 0xdd2040] Weighted P-Frames: Y:0.0% UV:0.0%
01-01 06:34:43.650: I/stderr(6603): [libx264 @ 0xdd2040] ref P L0: 81.2% 16.6%  1.8%  0.4%
01-01 06:34:43.650: I/stderr(6603): [libx264 @ 0xdd2040] ref B L0: 70.8% 29.2%
01-01 06:34:43.650: I/stderr(6603): [libx264 @ 0xdd2040] kb/s:287.21

    Edit: I want to know what determines rate factor? Is it relevant to fps? What is QP and it's relation with rate factor?

    Thank You!!

  • libx264 : which parameters can be changed on fly ?

    11 août 2015, par Dan Tumaykin

    I know that it is possible to change some encoder parameters on fly, using x264_encoder_reconfig(). From this commit I can deduce that we can change ratecontrol parameters - but I was unable to find a clear list of parameters that may be changed.

    Question: which parameters of x264 encoder can be changed on fly?

  • libx264 : change qp on fly

    11 août 2015, par jen

    I need dynamically change qp value during encoding for certain frames, but 264_encoder_try_reconfig function don't have that option. If I need change qp on fly, what should I do?

    Thanks, Jen

  • How to use ffmpeg for streaming mp4 via websocket

    5 août 2015, par curtiss

    I've written a sample in nodejs wich streams some input to the client via websocket connection in mp4 format. On the client side, the mp4 packages ar added to a MediaSourceBuffer.

    This runs fine, but only if the client gets the stream from the beginning with the first package. So another client can't play the current Stream, because he won't get the Stream from the beginning.

    I tried (try&error) to save the first package ffmpeg sends and send this at the beginning of a new connection, then the current stream. Then the MediaSourceBuffer breaks because of encoding error..

    Here is the ffmpeg command :

    -i someInput -g 59 
-vcodec libx264 -profile:v baseline 
-f mp4 -movflags empty_moov+omit_tfhd_offset+frag_keyframe+default_base_moof
-reset_timestamps 1
-

    The part "empty_moov+omit_tfhd_offset+frag_keyframe+default_base_moof" should make the Streampackages independet in putting the moovatom at the beginning of each part and sizing the parts in 59 frames each by keyframe, so i dont get it why i cant view the Stream beginning after the start.

  • Encoding IPIPIP Frames from x264 baseline 420 profile [duplicate]

    5 août 2015, par Codec Guy

    This question already has an answer here:

    I am new to FFMPEG. I am trying encode a stream in alternate I-Frames and P-Frames for the baseline profile IPIPIPIPIP.

    I searched FFMPEG forums but was not able to get the required output

    My script file:

    export LD_LIBRARY_PATH=:./FFMPEGEncLibs
./ffmpegEnc -f rawvideo -r 25 -s 176x144 -vcodec rawvideo -i ./encIn/akiyo_qcif.yuv -c:v libx264 -x264-params cabac=0:8x8dct=0 -pix_fmt yuv420p -profile:v baseline -level 4.1 -psnr -intra -qp 9 -vframes 10 ./encOut/akiyo_cif.h264

    Can someone suggest me changes to my script file, so that i would be able to encode in stream in IPIPIP format

    Thanks in advance

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