Video decoding

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This page is about players' video decoding feature. See also Video output and Audio decoding pages.

Introduction

This page provides information on how to best encode your video content (with or without audio) in terms of file format, video codecs, and encoding parameters, for playback on a SpinetiX device.

Note Notes:
  • The simplest way to test if a video is compatible with the HMP, is to drag & drop that video inside an Elementi project with the appropriate type (i.e., target HMP) correctly set up; if the video is imported, it means that the player can decode it, otherwise you'll be prompted to transcode the video (Elementi 2015 or later). You can also manually re-encode any video within Elementi after import.
  • To find out more details about your media file, you can also open it with MediaInfo application, VLC media player (Tools menu > Codec Information) or other similar applications.

Codecs

A video codec is software or a device that provides encoding and decoding for digital video, and which may or may not include the use of video compression and/or decompression. Several main, non-proprietary, video codecs are implemented on the player, as detailed below.

Supported video codecs

The following video codecs are implemented on the player:

  • H.265
    High Efficiency Video Coding (HEVC), also known as H.265 and MPEG-H Part 2, is a video compression standard designed as part of the MPEG-H project as a successor to the widely used Advanced Video Coding (AVC, H.264, or MPEG-4 Part 10). In comparison to AVC, HEVC offers from 25% to 50% better data compression at the same level of video quality, or substantially improved video quality at the same bit rate, and support for up to 8K resolutions. H.265 codec is supported only on HMP400/W and third-party players.
  • H.264 / MPEG-4 AVC
    Advanced Video Coding (AVC), also referred to as H.264 or MPEG-4 Part 10, Advanced Video Coding (MPEG-4 AVC) is a video compression standard that is one of the most commonly used formats for the recording, compression, and distribution of video content. The H.264 video format supports resolutions up to 8K and has a very broad application range that covers all forms of digitally compressed video from low bit-rate Internet streaming applications to HDTV broadcast and Digital Cinema applications with nearly lossless coding. H.264 should offer bit rate savings of 50% or more compared to MPEG-2 Part 2.
    Note that interlaced video should be avoided because it is supported only for “broadcast” resolutions known as 480i (720x480), 576i (720x576), and 1080i (1920x1080) at broadcast frame rates: 50, 59.94 or 60 fps - if unsure, re-encode the video within Elementi.
  • MPEG-4 Part 2
    MPEG-4 Part 2 or MPEG-4 Visual is a video compression format developed by MPEG. It belongs to the MPEG-4 ISO/IEC standards. The most commonly deployed profiles are Simple Profile (SP) and Advanced Simple Profile (ASP).
  • MPEG-2 (and MPEG-1)
    MPEG-2 (aka H.222/H.262 as defined by the ITU) is a standard for "the generic coding of moving pictures and associated audio information". MPEG-2 is widely used as the format of digital television signals that are broadcast by terrestrial (over-the-air), cable, and direct broadcast satellite TV systems. It also specifies the format of movies and other programs that are distributed on DVD and similar discs.
  • Windows Media Video 9 / VC-1
    VC-1 is a video codec specification that has been standardized by the SMPTE and implemented by Microsoft as Microsoft Windows Media Video (WMV) 9, in the form of 3 codecs (each identified with a unique four-character code): WMV3, WMVA (deprecated), and WVC1.
    Not supported on HMP200 or lower: Main Profile @ High Level (MP@HL) and the Advanced Profile (WVC1 / VC-1 Advanced Profile).
  • Motion JPEG
    Motion JPEG (M-JPEG or MJPEG) is a video compression format in which each video frame or interlaced field of a digital video sequence is compressed separately as a JPEG image (which is inefficient, using more bits to deliver similar quality, compared to more modern formats, such as H.264/MPEG-4 AVC). It is used by video-capture devices such as digital cameras, IP cameras, and webcams.
    Interlacing is not supported and for QuickTime formats, only MJPEG-A is supported (MJPEG-B is not supported).
Note Note:
See also the list of supported audio codecs.

Maximum resolution

The maximum resolution values below are recommended by SpinetiX based on square-pixel aspect ration for common usage.

Codec HMP400/HMP400W HMP350 HMP300 DiVA HMP200 HMP130 HMP100
H.265 / HEVC 4K60p x x x x x x
H.264 / MPEG-4 AVC 4K60p 1080p 1080p 1080p 1080p SD SD
MPEG4 Part 2 1080p 1080p 1080p 1080p 720p 720p SD
MPEG2 1080p 1080p 1080p 1080p 1080p 720p SD
Windows Media Video 9 / VC-1 1080p 1080p 1080p 1080p SD SD SD
Motion JPEG 1080p 1080p x x 720p 720p SD
Note Note:
The degree of support of the video codecs offered by each player is further detailed under "Encoding parameters" section.

Unsupported video codecs

This list is not exhaustive and any codec that is not written above should be considered as part of this list.

  • Flash video
  • Windows Media Video 8 (WMV2);
  • Lossless codecs / Uncompressed video (Quicktime Animation, RLE, DIB BMP, RGB);
  • RealVideo, Cook;
  • Interchange formats such as OMF / MXF;
  • MxPEG (proprietary, used by some low-power cameras), Motion JPEG 2000;
  • VP8, VP9.
Note Note:
See also the list of unsupported audio codecs.

Video file formats

A video file format is a type of file format for storing digital video data on a computer system. Video is almost always stored using lossy compression to reduce the file size. A video file normally consists of a container with video data in a video coding format (like H.264) alongside audio data in an audio coding format (like AAC). The container can also contain synchronization information, subtitles, and metadata such as title.

The following container formats are supported for files with video:

Name Extension Video codecs supported Audio codecs supported Notes
MPEG-4 Part 14 (MP4) .mp4, .m4v H.264/H.265, MPEG-2, MPEG-4 ASP AAC, MPEG Audio Layer I/II, MPEG Audio Layer III, AC-3, DTS MPEG-2 is not supported on HMP200, HMP130, and HMP100.
QuickTime File Format .mov, .qt H.264/H.265 , MPEG-4 ASP AAC
Audio Video Interleave .avi,.divx MPEG-4 ASP, MJPEG, MPEG-1, MPEG-2, H.264 MPEG Audio Layer III, MPEG Audio Layer I/II, AAC
Advanced Systems Format .wmv WMV9, VC-1 WMA2
DVD Video Object .vob MPEG-2, MPEG-1 MPEG Audio Layer I/II, AC-3, DTS Not supported by Fusion.
MPEG2 Program Stream .m2p, .mpegps MPEG-2, MPEG-1 MPEG Audio Layer I/II, MPEG Audio Layer III Not supported by Fusion.
MPEG2 Transport Stream .ts, .mpegts, .mp2t H.264/H.265, MPEG-2, VC-1 MPEG Audio Layer I/II, AAC, AC-3, DTS Not supported by Fusion.
Matroska Multimedia Container .mkv H.264/H.265, MPEG-2 AAC, MPEG Audio Layer I/II, MPEG Audio Layer III, AC-3, DTS Not supported on HMP200, HMP130, and HMP100.
Note Notes:
  • The highlighted item is the recommended one of the combination.
  • H.265 codec is supported only on HMP400/W and third-party players.
  • See also the audio file formats.
  • Some file formats only allow some types of codecs - see the Comparison of container formats page for a complete list.
  • VOB files must not be encrypted. Also, for older models, VOB files containing AC3 audio must have the audio transcoded into a suitable format like AAC, or have the audio track removed.
  • M4V is an Apple proprietary format which is unsupported, but for non-DRM-protected M4V and M4P files, often the file can be renamed to .MP4 and work correctly.
  • Closed captioning / subtitles streams included into the multimedia file are ignored by the player.
  • The following are partially supported container formats, which may work under undetermined restrictions and/or non optimal performance: .3gp, .3gpp, .3g2, .264, .mkv, .mpg, .mpeg, .mp2, .mp2v, .m2v, .m1v, .m4ves, .dv, .asf, .mjpg, .mjpeg, .ts.

Encoding parameters

The encoding parameters refer to all the other settings (e.g., codec profile & level, resolution, frames per second, bitrate etc.) that needs to be set correctly for the video / audio file to be decoded by the HMP. For instance, to address various applications ranging from low-quality, low-resolution surveillance cameras to high definition TV broadcasting and DVDs, many video standards group features into profiles and levels.

HMP400 and HMP400W

HMP400 and HMP400W

Profiles and levels:

HMP350 and HMP300

HMP350 and HMP300

Profiles and levels:

  • H.264 (aka MPEG4 Part 10) Constrained Baseline, Main or High profile up to level 4 (reference: H264 levels) - resolution up to 1080p.
  • MPEG-2: Simple and Main profile, up to High level (MP@HL)(reference: MPEG-2 profiles and levels) - resolution up to 1080p.
  • MPEG-4 (Part 2): Simple and Advanced Simple ( SP/ASP ) up to level 5. (reference: MPEG-4 levels) - resolution up to 1080p.
  • Windows Media Video 9 (WMV3): Advanced profiles, Level 3 - resolution up to 1080p.

HMP350 only

  • MJPEG - resolution up to 1080p.

DiVA

DiVA

Profiles and levels:

  • H.264 (aka MPEG4 Part 10) Constrained Baseline, Main or High profile up to level 4 (reference: H264 levels) - resolution up to 1080p.
  • MPEG-2: Simple and Main profile, up to High level (MP@HL)(reference: MPEG-2 profiles and levels) - resolution up to 1080p.
  • MPEG-4 (Part 2): Simple and Advanced Simple ( SP/ASP ) up to level 5. (reference: MPEG-4 levels) - resolution up to 1080p.
  • Windows Media Video 9 (WMV3): Advanced profiles, Level 3 - resolution up to 1080p.

HMP200

HMP200

Profiles and levels:

  • H.264 (aka MPEG4 Part 10) Constrained Baseline, Main or High profile up to level 4 (reference: H264 levels) - resolution up to 1080p.
  • MPEG-2: Simple and Main profile, up to High level (MP@HL)(reference: MPEG-2 profiles and levels) - resolution up to 1080p.
  • MPEG-4 (Part 2): Simple and Advanced Simple ( SP/ASP ) up to level 5. (reference: MPEG-4 levels) - resolution up to 720p.
    • MPEG4 video is limited to a maximum width or height of 1280 pixels and a maximum of 3600 macroblocks per frame. Release 3.0.0 was limited to an absolute vertical resolution of 864 pixels.
  • MJPEG - resolution up to 720p.
  • Windows Media Video 9 (WMV3): Simple and Main profiles, Low and Medium levels - resolution up to SD.
Note Notes:
  • MPEG-2 and H.264 are the most optimized codecs to use on the HMP200. MPEG-2 is using fewer processor resources than H.264, thus leaving more for other tasks, but the video itself will require a higher bitrate for the same quality. For more than two videos to be decoded at the same time, MPEG-2 should be preferred to H.264.
  • Please see Encoding guides if you need to convert your video to be supported.

HMP130 and HMP100

HMP130

Profiles and levels:

  • MPEG-4 (Part 2): Simple and Advanced Simple ( SP/ASP ) up to level 5 (reference: MPEG-4 levels) - resolution up to 720p for HMP130 and SD for HMP100.
  • MPEG-2: Simple and Main profile, up to Main level (MP@ML) (reference: MPEG-2 profiles and levels) - resolution up to 720p for HMP130 and SD for HMP100.
  • H.264 (aka MPEG4 Part 10) Constrained Baseline or Main profile up to level 3 (reference: H264 levels) - resolution up to SD.
  • MJPEG - resolution up to SD.
  • Windows Media Video 9 (WMV3): Simple and Main profiles, Low and Medium levels - resolution up to SD.
Note Notes:
  • MPEG-4 is the most optimized codec to use on the HMP100 & HMP130.
  • Please see Encoding guides if you need to convert your video to be supported.

Recommended bit rate

The values below are recommended by SpinetiX for optimal usage:

H.264 MPEG4 MPEG2
SD 2.5 Mbps [0.24 bpp] 3 Mbps [0.29 bpp] 5 Mbps [0.5 bpp]
720p 4.5 Mbps [0.2 bpp] 6.5 Mbps [0.29 bpp] 9 Mbps [0.4 bpp]
1080p 8 Mbps [0.16 bpp] - 16 Mbps [0.32 bpp]
Note Notes:
  • The maximum bitrate that can be supported can be deducted from the codec specification / constraints for video-only content.
  • Any video having a bit rate higher than 25Mbps should be transcoded. This can be done by Elementi 2015 or by other encoders.
  • SpinetiX has successfully tested at up to 50Mbps on the HMP350, 15 Mbps on the HMP200 and 11 Mbps on the HMP130 / HMP100.
  • MPEG-2 MP@HL states that the bit rate can go up to 80Mbps - that is probably outside the capabilities of the HMP and remains untested by SpinetiX.

Other notes

  • The specified video standards (e.g. 720p) are performance guides based on standard aspect ratio pixel equivalents; i.e. higher resolutions than 1280x720 could be displayed if the dimensions are adjusted proportionally.
  • Resolutions bigger than 1080p (like 4K videos) are not supported. Starting with Elementi 2015, such videos can be automatically transcoded to a format supported by the target HMP(s) and / or cut into smaller parts in the case of multiscreen content. Alternatively, you can do that manually - see Encoding guides for more details.
  • Interlaced video: HMP devices, using firmware 2.2.x or later, have a built-in de-interlacing filter for MPEG2 and H.264 videos.
  • Video transparency is partially supported.
  • The HMP supports some features relevant to video in addition to those in the SVG Tiny 1.2 specifications, such as rectangular clipping regions and elliptical arcs, however, masks and filters are not supported.

Troubleshooting

Video is not displayed

When a black image (green, on older firmware versions) is displayed instead of the video, it means that the video cannot be decoded by that player, most probably because the video is outside the player specifications (in which case you will find warning messages in the player.log, respectively on resources.log on older firmware versions).

Normally, Elementi / HMD would prevent importing that video inside the project, that is if the project type is set correctly. Similarly, the content creation tool or Fusion (in newer firmware versions) would also prevent uploading such a video.

Solution

See above the correct format, codec, and encoding parameters to use with the video files. Alternatively, you can re-encode the video within Elementi 2015 or later.

Video is rejected

A video that is outside the player specifications is rejected by Elementi 3.x / HMD upon import, because the HMP would display a black / green image instead of the video. The reason of rejecting that video file is also displayed; note that in Elementi, you need to click on the "Details..." button to get the full error message.

Similarly, the content creation tool or Fusion (in newer firmware versions) would also prevent uploading such a video.

Solution

Upgrade to Elementi 2015 or later, which allows re-encoding the video upon import. Alternatively, you can re-encode the video with a third-party application to make it compliant with the player specifications.
  • One common mistake is trying to import a Full HD video inside a project whose target player is HMP100 (default value when creating a new project) or HMP130, instead of HMP200. To correct this, right-click on the project, go over "Set Type" and select "HMP200 Project".

MPG files are not correctly played

Because the .mpg file extension is defined very vaguely, it is often mistakenly used as a container for MPEG2 program streams or transport streams (instead of .ts or .ps). Elementi / HMD allows importing a .mpg file, but usually the streams inside the file are not properly interpreted by the software / player, which results into audio / video sync loss or a totally wrong output.

Solution

  • If the file was suppose to be a .ts or .m2p, usually renaming the file should resolve the problem.
  • If the file was meant to be in a different container (like mp4, avi etc.), you can fix this problem by rewriting the streams into the proper container using a tool like ffmpeg - for instance, the following ffpeg command rewrites the file "inputfile.mpg" into "outputfile.mp4":
    ffmpeg.exe -i inputfile.mpg -codec: copy outputfile.mp4

Video is not smooth

Playing a 25 fps video on an player set to output a video signal at 60Hz may lead to a non-smooth effect on the screen; same thing applies for 30 fps video played at 50Hz.

This is due to the fact that player must compensate for 60 / 25 not being an integer value; so to output 60 images per second, the player must display each frame of the original video twice (that's 50 images), while some frames (evenly distributed) are displayed three time, to cover for the missing 10 images. This last part of the process can affect the smoothness of the video playback. A similar process is done for 30 fps video played at 50Hz and for 24 fps videos.

Solution:

To improve the smoothness, it is recommended to set the player output at 50Hz for 25fps video, respectively at 60Hz for 30 fps videos. In case of having videos at 24 fps or a mix of videos at different fps, the best is to set the player output to 60Hz.

Image freeze or audio lost

This is the result of a non-optimal multiplexing of the audio and video streams that requires more than 1 MB of buffering of the audio or video stream in order to keep it in sync with the other. In this case the player.log has the following error:
Stream demuxing failed because more than 1048576 bytes of buffering is required

Solution:

Re-encoding the media, either within Elementi 2015 (or later) or with another application (like FFMpeg) should fix the image freeze or the audio lost. Alternatively, the spx:maxDemuxingBufferSize attribute could be increased.

See also

This page was last modified on 29 September 2020, at 14:16.