NGINX-based VOD Packager

nginx-vod-module

Join the list of organizations using this video packager project.

Features

• On-the-fly repackaging of MP4 files to DASH, HDS, HLS, MSS

• Working modes:

  1. Local - serve locally accessible files (local disk/NFS mounted)
  2. Remote - serve files accessible via HTTP using range requests
  3. Mapped - serve files according to a specification encoded in JSON format. The JSON can pulled from a remote server, or read from a local file

• Adaptive bitrate support

• Playlist support (playing several different media files one after the other) - mapped mode only

• Simulated live support (generating a live stream from MP4 files) - mapped mode only

• Fallback support for file not found in local/mapped modes (useful in multi-datacenter environments)

• Video codecs: H264, H265 (DASH/HLS), VP9 (DASH)

• Audio codecs: AAC, MP3 (HLS/HDS/MSS), AC-3 (DASH/HLS), E-AC-3 (DASH/HLS), OPUS (DASH)

• Captions support -

  Input:

  1. WebVTT
  2. SRT
  3. DFXP/TTML
  4. CAP (Cheetah)

  Output:

  1. DASH - served as a single WebVTT
  2. HLS - segmented WebVTT (m3u8)
  3. MSS - converted to TTML and packaged in fragmented MP4 (no support for styling)

• Audio only/video only files

• Alternative audio renditions - supporting both:

  1. Generation of manifest with different audio renditions, allowing selection on the client side
  2. Muxing together audio and video streams from separate files / tracks - provides the ability
     to serve different audio renditions of a single video, without the need for any special support
     on the client side.

• Track selection for multi audio/video MP4 files

• Playback rate change - 0.5x up to 2x (requires libavcodec and libavfilter)

• Source file clipping (only from I-Frame to P-frame)

• Support for variable segment lengths - enabling the player to select the optimal bitrate fast,
  without the overhead of short segments for the whole duration of the video

• Clipping of MP4 files for progressive download playback

• Thumbnail capture (requires libavcodec) and resize (requires libswscale)

• Volume map (requires libavcodec) - returns a CSV containing the volume level in each interval

• Decryption of CENC-encrypted MP4 files (it is possible to create such files with MP4Box)

• DASH: common encryption (CENC) support

• MSS: PlayReady encryption support

• HLS: Generation of I-frames playlist (EXT-X-I-FRAMES-ONLY)

• HLS: support for AES-128 / SAMPLE-AES encryption

Limitations

• Track selection and playback rate change are not supported in progressive download

• I-frames playlist generation is not supported when encryption is enabled

• Tested on Linux only

Compilation

Dependencies

In general, if you have the dependencies that are required to build nginx, you should be able to build nginx-vod-module.
However, some optional features of this module depend on additional packages. The module detects these packages
during configure - if a package is missing, the respective feature will be disabled.

The optional features are:

1. Thumbnail capture & volume map - depend on ffmpeg (3.0 or newer)
2. Audio filtering (for changing playback rate / gain) - depends on ffmpeg (3.0 or newer) and also on libfdk_aac.
   Due to licensing issues, libfdk_aac is not built into kaltura ffmpeg packages
3. Encryption / decryption (DRM / HLS AES) - depends on openssl
4. DFXP captions - depends on libxml2
5. UTF-16 encoded SRT files - depends on iconv

Build

To link statically against nginx, cd to nginx source directory and execute:

./configure --add-module=/path/to/nginx-vod-module
make
make install

To compile as a dynamic module (nginx 1.9.11+), use:

./configure --add-dynamic-module=/path/to/nginx-vod-module

In this case, the load_module directive should be used in nginx.conf in order to load the module.

Optional recommended settings:

1. --with-file-aio - enable asynchronous I/O support, highly recommended, relevant only to local and mapped modes
2. --with-threads (nginx 1.7.11+) - enable asynchronous file open using thread pool (also requires vod_open_file_thread_pool in nginx.conf), relevant only to local and mapped modes
3. --with-cc-opt="-O3" - enable additional compiler optimizations (we saw about 8% reduction in the mp4 parse time
   and frame processing time compared to the nginx default -O)

Debug settings:

1. --with-debug - enable debug messages (also requires passing debug in the error_log directive in nginx.conf).
2. --with-cc-opt="-O0" - disable compiler optimizations (for debugging with gdb)

Installation

RHEL/CentOS 6/7 RPM

# rpm -ihv http://installrepo.kaltura.org/releases/kaltura-release.noarch.rpm
# yum install kaltura-nginx

Debian/Ubuntu deb package

Ubuntu NOTE: before trying to install kaltura-nginx, you must also make sure the multiverse repo is enabled

For Debian Wheezy [7], Debian Jessie [8], Ubuntu 14.04 and 14.10, add this repo:

# wget -O - http://installrepo.kaltura.org/repo/apt/debian/kaltura-deb-curr.gpg.key