Upper limit on FFMPEG/libx264 frame sizes?

Question

I'm trying to use FFMPEG to transcode a video with very large frames (4096 x 4096). It's a short video - just under two minutes, but the source video file is 15.8GB. (The video is an animation designed to be projected onto planetarium domes.)

The source file is a Quicktime MOV containing uncompressed Photo-JPEG images (with audio, too). When I tell FFMPEG to transcode my MOV file into an MP4 file, it simply says:

Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height

Not very helpful, but yes, I've verified that all of the parameters are correct and/or defaults. In fact, if I change the requested output size to 2048x2048, then everything works just fine. That's why I suspect that there's an upper bound in the encoder.

I am kerflummoxed. Any suggestions that result in a successful transcode will be greatly appreciated. (At this point I am also willing to consider alternatives to FFMPEG.)

The Facts

I run FFMPEG from a script:

set srcFile=%1
set dstFile=%srcFile:.mov=.mp4%

ffmpeg -i %srcFile% -movflags faststart -q:a 0 -q:v 0 -pix_fmt yuv420p -sws_flags gauss -s 4096x4096 %dstFile%

The Output

    ffmpeg version N-50911-g9efcfbe Copyright (c) 2000-2013 the FFmpeg developers
    built on Mar 13 2013 21:26:48 with gcc 4.7.2 (GCC)
    configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-libass --enable-libbluray --enable-libcaca --enable-libfreetype --enable-libgsm --enable-libilbc --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --ena
ble-libopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxavs --enable-libxvid --enable-zlib
  libavutil      52. 19.100 / 52. 19.100
  libavcodec     55.  0.100 / 55.  0.100
  libavformat    55.  0.100 / 55.  0.100
  libavdevice    54.  4.100 / 54.  4.100
  libavfilter     3. 45.103 /  3. 45.103
  libswscale      2.  2.100 /  2.  2.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  2.100 / 52.  2.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'also-sprach-zarathustra-4k.mov':
  Metadata:
    major_brand     : qt
    minor_version   : 537199360
    compatible_brands: qt
    creation_time   : 2013-01-11 23:41:30
  Duration: 00:01:40.57, start: 0.000000, bitrate: 1357694 kb/s
    Stream #0:0(eng): Audio: pcm_s16be (twos / 0x736F7774), 44100 Hz, stereo, s16, 1411 kb/s
    Metadata:
      creation_time   : 2013-01-11 23:41:30
      handler_name    : Apple Alias Data Handler
    Stream #0:1(eng): Video: mjpeg (jpeg / 0x6765706A), yuvj420p, 4096x4096 [SAR 1:1 DAR 1:1], 1356281 kb/s, 30 fps, 30
tbr, 3k tbn, 3k tbc
    Metadata:
      creation_time   : 2013-01-11 23:41:30
      handler_name    : Apple Alias Data Handler
File 'also-sprach-zarathustra-4k.mp4' already exists. Overwrite ? [y/N] y
using SAR=1/1
[libx264 @ 003b9c80] frame MB size (256x256) > level limit (36864)
[libx264 @ 003b9c80] DPB size (4 frames, 262144 mbs) > level limit (2 frames, 184320 mbs)
[libx264 @ 003b9c80] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX AVX2 FMA3 LZCNT BMI1 BMI2
x264 [error]: malloc of size 17305600 failed
Output #0, mp4, to 'also-sprach-zarathustra-4k.mp4':
  Metadata:
    major_brand     : qt
    minor_version   : 537199360
    compatible_brands: qt
    Stream #0:0(eng): Video: h264, yuv420p, 4096x4096 [SAR 1:1 DAR 1:1], q=-1--1, 90k tbn, 30 tbc
    Metadata:
      creation_time   : 2013-01-11 23:41:30
      handler_name    : Apple Alias Data Handler
    Stream #0:1(eng): Audio: none, 44100 Hz, stereo, s16, 128 kb/s
    Metadata:
      creation_time   : 2013-01-11 23:41:30
      handler_name    : Apple Alias Data Handler
Stream mapping:
  Stream #0:1 -> #0:0 (mjpeg -> libx264)
  Stream #0:0 -> #0:1 (pcm_s16be -> libvo_aacenc)
Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height

PS: Yes, for those playing at home, it is the theme to 2001 - A Space Odyssey. You can see a 1K YouTube version here: 2001 - A Fulldome Space Odyssey And yes, in a planetarium with a good sound system, it is absolutely EPIC.

Solution 1

I think you're actually running into the limitation of of x264's codec complexity levels.

Brief description of the levels from http://en.wikipedia.org/wiki/H.264/MPEG-4_AVC

As the term is used in the standard, a "level" is a specified set of constraints that indicate a degree of required decoder performance for a profile. For example, a level of support within a profile specifies the maximum picture resolution, frame rate, and bit rate that a decoder may use. A decoder that conforms to a given level must be able to decode all bitstreams encoded for that level and all lower levels.

The max resolution for the highest level (5.2) is 4,096×2,304.

I would look into using HEVC which is specifically designed for these larger format 4K / Ultra-HD resolutions.

http://en.wikipedia.org/wiki/HEVC

Max Resolution for HEVC is currently 8,192x4,320

Solution 2

I suspect your problem is hinted at here:

x264 [error]: malloc of size 17305600 failed

Is this a 32-bit build of ffmpeg? If so, I fear you may be out of luck. 4k video processing really requires >4 GB of memory. Better switch to a 64-bit build and try again.

Of course you actually need to have enough memory available in your computer, too. It could be a lot more than 4 GB, depending on your x264 settings.

Comments

[Xeoncross]

I know what I'm going to be building this weekend

[Chaotic]

Thanks for the links. They answered my core question, and in fact they've answered a future question: is there any (popular/standard) codec out there that can handle 8Kx8K? 12Kx12K? You laugh, but my videos are already being played back through 8Kx8K 60fps stereoscopic projection systems. By 2020 I expect this to peak out at 16Kx16K 60fps, which (for medium-to-large domes) is approaching retina levels. Thanks for the pointer to HEVC. I'm not sure it actually solves my problem today, unfortunately, since it's not ubiquitous yet. On the other hand, it's almost certainly the future.

[Chaotic]

Nope. I saw that, too, so I double-checked that right away. I'm all 64-bit here, guaranteed. (I have a monster system here - latest quad-core i7, 32GB RAM, NVIDIA Titan card, wicked fast disks, etc.)

[njahnke]

Good catch that no level for H.264 allows 4k x 4k video. I'm still surprised that x264 failed in malloc() though. That seems like a bug.

[Chaotic]

Good news! I had foolishly installed ImageMajick, which installs its OWN version of FFMPEG in the path. On a whim I did 'where ffmpeg' only to discover that, much to my surprise, I was running a much older (and probably 32-bit) version of FFMPEG. All is well! I am now able to compress a 4K MOV file into a 4K MP4 file. Thanks to everyone for suggestions, and especially @njahnke for making me continue to question my sanity.

[Sergio Basurco]

It's not your system but the Libav build that needs to be 64-bit.

[James]

Thanks for this answer; it seems that imagemagick on Windows thinks its 4 year old build of ffmpeg should go earlier in the system path then whatever one you have installed. Don't think I'm getting those three minutes of swearing back.