MPEG

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Revision as of 05:18, 2 February 2019 by DoesItReallyMatter (talk | contribs) (New page anchors: #TS for "TS, MPEG2 Transport Stream", #PS for "PS, aka MPEG Program Stream")
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Wikipedia has information on this entry:
MPEG

MPEG refers to a set of standards created by the Moving Picture Experts Group. MPEG refers to several video, audio and container formats; see the full list at the Codec page.

An MPEG file is a file using an MPEG container (these are called mpeg1, ts, ps, and mp4 for MPEG-4).

Creating an MPEG File with VLC

To make an MPEG file, you need to:

  • Pick a container (see below)
  • Transcode the audio and video to formats able to be held in the container: in general this is the MPEG video and audio formats only. Check the compatibility information in the official documentation, but be warned that while VLC allows any codec and mux, most other players support only a few combinations!

MPEG-1 and 2

Wikipedia has information on this entry:
MPEG-1
Wikipedia has information on this entry:
MPEG-2
  • Muxer: ts, ps, mpeg1

MPEG-1 is a video and audio compression format, used in Video CDs. It is compatible with a large number of software and hardware devices.

Here is an example of how to transcode an AVI into a portable MPEG-1 video from the command prompt 

% vlc file.avi --sout='#transcode{vcodec=mp1v, acodec=mpga}:std{access=file, mux=mpeg1,url=file.mpg}'

MPEG-2 is used in digital television and DVB. It is also used as the format for DVDs. The biggest advantage of this format over MPEG-1 is in its support for interlaced pictures; MPEG-2 can cleanly compress interlaced video, while MPEG-1 internally only works on progressive-scan video, so interlacing must be faked.

Here is an example of how to transcode an AVI into an MPEG-2 video from the command prompt 

% vlc file.avi --sout='#transcode{vcodec=mp2v, acodec=mpga}:std{access=file, mux=ps,url=file.mpg}'

Transcoding and Streaming

According to bug #1965, (Note: this bug has since been fixed) in order to transcode and stream an MPEG-1 or MPEG-2 payload, you MUST supply a framerate of 25 fps to the transcoder. Here's an example: 

% :sout=#transcode{vcodec=mp2v,vb=30,fps=25,scale=1,...}

When using the GUI, this must be done by adding or editing a profile under "Transcoding Options," and changing the "Frame Rate" field under the "Video Codec" tab to 25.

HINT: Use an MPEG-TS (transport) stream container if you are streaming MPEG through the network (see Container Formats).

Video

mp1v
 This is a video codec. The name to use at the command line is mp1v.
mp2v
 This is a video codec. The name to use at the command line is mp2v, but you can also use mpgv.
mp4v
 This is a video codec. The name to use at the command line is mp4v.
h264
 This is a video codec. The name to use at the command line is h264.

Codecs for MPEG-1 Video, MPEG-2 Video, MPEG-4 Video and H.264 Video (MPEG-4 AVC).

Audio

mpga
 This is an audio codec. The name to use at the command line is mpga.
mp3
 This is an audio codec. The name to use at the command line is mp3.
mp4a
 This is an audio codec. The name to use at the command line is mp4a.

Codecs for MPEG Layer 1/2 audio, MPEG Layer 3 audio and MPEG-4 AAC audio

Container formats

MPEG-2 specified 2 container formats, ts and ps. Containers hold video and audio information in them, and package them up so it can be sent over a network or stored on disk.

  • ts (Transport Stream) should be used to store or send data where data loss will probably occur, such as over a network.
  • ps (Program Stream) should be used to store or send data where data loss is not likely, such as on a DVD.

Both ps and ts can transport MPEG-4 Video, but only ts can send MPEG-4 Audio. In addition, MPEG-4 specifies its own container format, mp4 (see MPEG-4)

TS, MPEG2 Transport Stream

ts
 VLC can encode and decode this container.
The module name to use at the command line is ts.
Module options
  • --ts-extra-pmt (string)
    Extra PMT. Allows a user to specify an extra pmt (pmt_pid=pid:stream_type[,...]).
  • --ts-es-id-pid" (boolean)

Set the internal ID of each elementary stream handled by VLC to the same value as the PID in the TS stream, instead of 1, 2, 3, etc. Useful to do '#duplicate{..., select="es=<pid>"}'."). Default is true.

  • --ts-out (string)
    Fast UDP streaming. Sends TS to specific ip:port by udp (you must know what you are doing). Default off.
  • --ts-out-mtu (integer)
    MTU for out mode. Default 1500.
  • --ts-csa-ck (string)
    Control word for the CSA encryption algorithm.
  • --ts-csa-pkt (integer)
    Default: 188
  • --ts-silent (boolean)
    Supresses complaints for encrypted PES. Default false.
  • --ts-dump-file (file name)
    A filename do dump ts into.
  • --ts-dump-append (boolean)
    Append data to the dump file. Default is false, which overwrites the file.
  • --ts-dump-size (integer)
    The size of the buffer for reading/writing an integer number of packets. Default: 16384 bytes.
Accepted video codecs
  • mp1v: MPEG-1 video
  • mpgv: MPEG-1 or MPEG-2 video
  • mp4v: MPEG-4 video (ASP)
  • h264: H.264, MPEG-4 AVC
  • drac: Dirac
  • jpeg
  • ms: MS codecs (nonstandard?)
Accepted audio codecs
Accepted subtitle codecs

PS, aka MPEG Program Stream

ps
 VLC can encode and decode this container.
The module name to use at the command line is ps.
Module options
  • --ps-trust-timestamps (boolean)
    Turns on or off trusting the timestamps in the file. Set as false to work it out from the bitrates. Default true.
Accepted video codecs
Accepted audio codecs
Accepted subtitle codecs

MPEG-3

Wikipedia has information on this entry:
MPEG-3

A largely unused audio and video compression format.

  • Note that the amazingly common MP3 audio files are actually MPEG-1 Layer 3 audio, not MPEG-3.

MPEG-4

See MPEG-4.

Source code

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