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).
Contents
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
- 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
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This is a video codec. The name to use at the command line is mp1v. |
mp2v
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This is a video codec. The name to use at the command line is mp2v, but you can also use mpgv. |
mp4v
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This is a video codec. The name to use at the command line is mp4v. |
h264
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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
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This is an audio codec. The name to use at the command line is mpga. |
mp3
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This is an audio codec. The name to use at the command line is mp3. |
mp4a
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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-standard <string> auto,mpeg,dvb,arib,atsc,tdmb : Selects mode for digital TV standard. This feature affects EPG information and subtitles default value: auto
- ts-extra-pmt <string> : Allows a user to specify an extra pmt (
pmt_pid=pid:stream_type[,...]) default value: NULL - ts-trust-pcr <boolean> : Use the stream PCR as a reference default value: enabled
- 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 value: enabled - ts-csa-ck <string> : CSA encryption key. This must be a 16 char string (8 hexadecimal bytes) default value: NULL
- ts-csa2-ck <string> : The even CSA encryption key. This must be a 16 char string (8 hexadecimal bytes) default value: NULL
- ts-csa-pkt <integer> : Specify the size of the TS packet to decrypt. The decryption routines subtract the TS-header from the value before decrypting default value: 188
- ts-split-es <boolean> : Separate teletex/dvbs pages into independent ES. It can be useful to turn off this option when using stream output default value: enabled
- ts-seek-percent <boolean> : Seek and position based on a percent byte position, not a PCR generated time position. If seeking doesn't work property, turn on this option default value: disabled
- ts-cc-check <boolean> : Detect discontinuities and drop packet duplicates. (bluRay sources are known broken and have false positives) default value: enabled
- ts-pmtfix-waitdata <boolean> : Only create ES on program sending data default value: enabled
- ts-patfix <boolean> : Try to generate PAT/PMT if missing default value: enabled
- ts-pcr-offsetfix <boolean> : Try to fix too early PCR (or late DTS) default value: enabled
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> : Normally we use the timestamps of the MPEG files to calculate position and duration. However sometimes this might not be usable. Disable this option to calculate from the bitrate instead default value: enabled
Accepted video codecs
Accepted audio codecs
Accepted subtitle codecs
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
- modules/mux/mp4/mp4.c (output muxer)
- modules/demux/mpeg/ps.c (input demuxer)
- modules/demux/mpeg/ts.c (input demuxer)
- modules/demux/mpeg/ps.h (input demuxer)
