Ziki
Ziki

Reputation: 1440

FFMPEG-jpg sequence to H.264 generate best result

I have a jpg sequence which I need to convert to mp4, and I need to get the best result.

As I understood, I need to supply the 'ffmpeg' cmdln the following: bitrate, minrate, maxrate and bufsize.

The only thing that I found about calculating the above params, is if I have the final output file size. But considering I want the best quality, I don't know the final output file size, and I don't care what it will be.

Of course I have the framerate and the total frames.

Here's my ffmpeg cmdln:

ffmpeg 
-r 24 
-start_number 0 
-i "C:\pathToSequence\%06d.jpg" 
-c copy 
-vframes 792 
-threads 16 
-pix_fmt yuv420p 
-c:v libx264 
"C:\pathToOutput\result.mp4"

The total size of the sequence is 128MB, 792 frames, 24 framerate, resolution 1280x720.

Until now I used to add the following to the ffmpeg cmdln:

-b:v 10000k -minrate 10000k -maxrate 10000k -bufsize 10000k

And if it was 1080p:

-b:v 20000k -minrate 20000k -maxrate 20000k -bufsize 20000k

And I figured that if I put the max value that ffmpeg can handle (2147480) it will generate almost the same result as the above. But I think it's a bad approach(correct me if I'm wrong).

So if I need to get the best result, how do I calculate it(or I can simply put the max value)?

Also I would like if you have another helpful flags to add to make the best final result.

--EDIT--

Here's the updated command:

O:\tools\ffmpeg -framerate 24 -start_number 0 -i "C:\share\localProcess\test\%05d.jpg" -vframes 54 -pix_fmt yuv420p -c:v libx264 -preset veryslow -qp 1 "C:\share\localProcess\result\result.mp4"

And this is the ouptout:

ffmpeg version N-72383-g7206b94 Copyright (c) 2000-2015 the FFmpeg developers
  built with gcc 4.9.2 (GCC)
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libdcadec --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmfx --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-lzma --enable-decklink --enable-zlib
  libavutil      54. 26.100 / 54. 26.100
  libavcodec     56. 41.100 / 56. 41.100
  libavformat    56. 33.101 / 56. 33.101
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5. 16.101 /  5. 16.101
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  3.100 / 53.  3.100
Input #0, image2, from 'C:\share\localProcess\test\%05d.jpg':
  Duration: 00:00:02.25, start: 0.000000, bitrate: N/A
    Stream #0:0: Video: mjpeg, yuvj444p(pc, bt470bg/unknown/unknown), 1280x720 [SAR 72:72 DAR 16:9], 24 fps, 24 tbr, 24 tbn, 24 tbc
[swscaler @ 0000000004d6bf60] deprecated pixel format used, make sure you did set range correctly
[libx264 @ 0000000004d7a9e0] using SAR=1/1
[libx264 @ 0000000004d7a9e0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 AVX2 LZCNT BMI2
[libx264 @ 0000000004d7a9e0] profile High, level 5.0
[libx264 @ 0000000004d7a9e0] 264 - core 146 r2538 121396c - H.264/MPEG-4 AVC codec - Copyleft 2003-2015 - http://www.videolan.org/x264.html - options: cabac=1 ref=16 deblock=1:0:0 analyse=0x3:0x133 me=umh subme=9 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=24 chroma_me=1 trellis=2 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=12 lookahead_threads=2 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=8 b_pyramid=2 b_adapt=2 b_bias=0 direct=3 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=24 scenecut=40 intra_refresh=0 rc=cqp mbtree=0 qp=1 ip_ratio=1.40 pb_ratio=1.30 aq=0
Output #0, mp4, to 'C:\share\localProcess\result\result.mp4':
  Metadata:
    encoder         : Lavf56.33.101
    Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], q=-1--1, 24 fps, 12288 tbn, 24 tbc
    Metadata:
      encoder         : Lavc56.41.100 libx264
Stream mapping:
  Stream #0:0 -> #0:0 (mjpeg (native) -> h264 (libx264))
Press [q] to stop, [?] for help
frame=   54 fps= 38 q=-1.0 Lsize=     542kB time=00:00:02.16 bitrate=2050.0kbits/s
video:541kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.251171%
[libx264 @ 0000000004d7a9e0] frame I:1     Avg QP: 0.00  size: 23629
[libx264 @ 0000000004d7a9e0] frame P:22    Avg QP: 1.00  size: 16146
[libx264 @ 0000000004d7a9e0] frame B:31    Avg QP: 2.81  size:  5623
[libx264 @ 0000000004d7a9e0] consecutive B-frames: 16.7% 29.6% 16.7%  0.0%  9.3%  0.0% 13.0% 14.8%  0.0%
[libx264 @ 0000000004d7a9e0] mb I  I16..4: 74.9% 20.2%  4.9%
[libx264 @ 0000000004d7a9e0] mb P  I16..4:  0.3%  0.1%  1.2%  P16..4:  2.7%  0.4%  0.8%  0.2%  0.1%    skip:94.2%
[libx264 @ 0000000004d7a9e0] mb B  I16..4:  0.0%  0.0%  0.0%  B16..8:  3.0%  0.4%  0.5%  direct: 0.3%  skip:95.7%  L0:56.0% L1:40.5% BI: 3.5%
[libx264 @ 0000000004d7a9e0] 8x8 transform intra:16.5% inter:18.4%
[libx264 @ 0000000004d7a9e0] direct mvs  spatial:54.8% temporal:45.2%
[libx264 @ 0000000004d7a9e0] coded y,uvDC,uvAC intra: 33.9% 49.8% 49.5% inter: 1.3% 2.9% 2.9%
[libx264 @ 0000000004d7a9e0] i16 v,h,dc,p: 79% 13%  4%  4%
[libx264 @ 0000000004d7a9e0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 12% 22% 48%  2%  4%  6%  3%  1%  2%
[libx264 @ 0000000004d7a9e0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 13% 13% 43%  5%  6%  4%  5%  5%  6%
[libx264 @ 0000000004d7a9e0] i8c dc,h,v,p: 78% 12%  7%  3%
[libx264 @ 0000000004d7a9e0] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 0000000004d7a9e0] ref P L0: 65.7%  2.4%  8.9%  4.5%  2.3%  3.0%  2.8%  3.9%  3.5%  0.8%  0.3%  0.5%  0.3%  0.5%  0.2%  0.3%
[libx264 @ 0000000004d7a9e0] ref B L0: 76.9% 12.0%  3.4%  0.7%  3.6%  0.5%  2.1%  0.4%  0.1%  0.0%  0.1%  0.0%  0.1%  0.1%
[libx264 @ 0000000004d7a9e0] ref B L1: 98.2%  1.8%
[libx264 @ 0000000004d7a9e0] kb/s:1966.80

Link to download JPG sequence.

Link to download the result.

Upvotes: 1

Views: 3956

Answers (1)

llogan
llogan

Reputation: 133703

Just use -crf and -preset (when using libx264)

  • Use the highest -crf value that still gives you an acceptable quality. Range is a log scale of 0-51: 0 is lossless (huge files), 18 is "visually lossless" or nearly so, 23 is default, and worst is 51.

  • Use the slowest -preset you have patience for: ultrafast, superfast, veryfast, faster, fast, medium, slow, slower, veryslow. Default is "medium".

See FFmpeg Wiki: H.264 Video Encoding Guide for more info.

Other stuff

  • As an input option, you should use -framerate instead of -r when using the image file demuxer.

  • libx264 automatically chooses an optimal number of threads, so manually forcing a certain value with -threads may be suboptimal.

  • -start_number 0 is superfluous.

  • -c copy and -c:v libx264 are mutually exclusive in your example (you only have one input stream and it is a a video stream), so in this case -c copy is being ignored.

  • Consider adding -movflags +faststart if your video will be viewed via progressive download (such as someone typically watching it in a browser or phone).

Upvotes: 2

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