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encoding-profile: Cleanup profile serialization documentation
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/1002>
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Thibault Saunier
GStreamer Merge Bot
parent
57029ba098
commit
a8fdaba2ab
1 changed files with 44 additions and 32 deletions
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@ -37,53 +37,60 @@
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* reference one or more #GstEncodingProfile(s) which indicate which encoding
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* format should be used on each individual streams.
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*
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* #GstEncodingProfile(s) can be provided to the 'encodebin' element, which
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* will take care of selecting and setting up the required elements to produce
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* an output stream conforming to the specifications of the profile.
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* #GstEncodingProfile(s) can be provided to the 'encodebin' element, which will
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* take care of selecting and setting up the required elements to produce an
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* output stream conforming to the specifications of the profile.
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*
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* Unlike other systems, the encoding profiles do not specify which #GstElement
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* to use for the various encoding and muxing steps, but instead relies on
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* specifying the format one wishes to use.
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* The encoding profiles do not necessarily specify which #GstElement to use for
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* the various encoding and muxing steps, as they allow to specifying the format
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* one wishes to use.
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*
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* Encoding profiles can be created at runtime by the application or loaded
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* from (and saved to) file using the #GstEncodingTarget API.
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* Encoding profiles can be created at runtime by the application or loaded from
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* (and saved to) file using the #GstEncodingTarget API.
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*
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* ## Defining a GstEncodingProfile as a string
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* ## The encoding profile serialization format
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*
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* ### Serialized encoding profile formats
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* Encoding profiles can be serialized to be used in the command line tools or
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* to set it on other other #GObject-s using #gst_util_set_object_arg for
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* example.
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*
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* #### Using encoders and muxer element factory name:
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* The serialization format aims at being simple to understand although flexible
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* enough to describe any possible encoding profile. There are several ways to
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* describe the profile depending on the context but the general idea is that it
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* is a colon separated list of EncodingProfiles descriptions, the first one
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* needs to describe a #GstEncodingContainerProfile and the following ones
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* describe elementary streams.
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*
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* ### Using encoders and muxer element factory name
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*
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* ```
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* muxer_factory_name:video_encoder_factory_name:audio_encoder_factory_name
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* ```
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*
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* For example to encode a stream into a WebM container, with an OGG audio
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* stream and a VP8 video stream, the serialized #GstEncodingProfile looks
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* like:
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* stream and a VP8 video stream, the serialized #GstEncodingProfile looks like:
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*
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* ```
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* webmmux:vp8enc:vorbisenc
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* ```
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*
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* #### Define the encoding profile in a generic way using caps:
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* ### Define the encoding profile in a generic way using caps:
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*
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* ```
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* muxer_source_caps:video_encoder_source_caps:audio_encoder_source_caps
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* ```
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*
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* For example to encode a stream into a WebM container, with an OGG audio
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* stream and a VP8 video stream, the serialized #GstEncodingProfile looks
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* like:
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* stream and a VP8 video stream, the serialized #GstEncodingProfile looks like:
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*
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* ```
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* video/webm:video/x-vp8:audio/x-vorbis
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* ```
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*
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* It is possible to mix caps and element type names so you can specify a specific
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* video encoder while using caps for other encoders/muxer.
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* It is possible to mix caps and element type names so you can specify a
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* specific video encoder while using caps for other encoders/muxer.
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*
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* ### Advanced encoding format serialization features:
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* ### Using preset
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*
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* You can also set the preset name of the encoding profile using the
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* caps+preset_name syntax as in:
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@ -92,6 +99,8 @@
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* video/webm:video/x-vp8+youtube-preset:audio/x-vorbis
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* ```
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*
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* ### Setting properties on muxers or on the encoding profile itself
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*
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* Moreover, you can set extra properties `presence`, `single-segment` and
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* `variable-framerate` * of an * encoding profile using the `|presence=` syntax
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* as in:
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@ -104,15 +113,17 @@
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* #GstEncodingProfile can be used inside an encodebin. If 0, it is not a
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* mandatory stream and can be used as many times as necessary.
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*
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* ### Enforcing properties to the stream itself (video size, number of audio channels, etc..)
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*
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* You can also use the `restriction_caps->encoded_format_caps` syntax to
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* specify the restriction caps to be set on a #GstEncodingProfile
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*
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* It corresponds to the restriction #GstCaps to apply before the encoder that
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* will be used in the profile. The fields present in restriction caps are
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* properties of the raw stream (that is, before encoding), such as height and
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* width for video and depth and sampling rate for audio. This property does
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* not make sense for muxers. See #gst_encoding_profile_get_restriction for
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* more details.
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* will be used in the profile (See #gst_encoding_profile_get_restriction). The
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* fields present in restriction caps are properties of the raw stream (that is,
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* before encoding), such as height and width for video and depth and sampling
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* rate for audio. This property does not make sense for muxers. See
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* #gst_encoding_profile_get_restriction for more details.
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*
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* To force a video stream to be encoded with a Full HD resolution (using WebM
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* as the container format, VP8 as the video codec and Vorbis as the audio
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@ -125,27 +136,28 @@
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* > NOTE: Make sure to enclose into quotes to avoid '>' to be reinterpreted by
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* > the shell.
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*
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* In the case you are using encoder types, the following is also possible:
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* In the case you are specifying encoders directly, the following is also
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* possible:
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*
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* ```
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* "matroskamux:x264enc,width=1920,height=1080:audio/x-vorbis"
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* matroskamux:x264enc,width=1920,height=1080:audio/x-vorbis
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* ```
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*
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* ## Some serialized encoding formats examples:
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* ## Some serialized encoding formats examples
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*
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* MP3 audio and H264 in MP4:
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* ### MP3 audio and H264 in MP4**
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*
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* ```
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* video/quicktime,variant=iso:video/x-h264:audio/mpeg,mpegversion=1,layer=3
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* ```
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*
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* Vorbis and theora in OGG:
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* ### Vorbis and theora in OGG
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*
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* ```
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* application/ogg:video/x-theora:audio/x-vorbis
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* ```
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*
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* AC3 and H264 in MPEG-TS:
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* ### AC3 and H264 in MPEG-TS
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*
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* ```
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* video/mpegts:video/x-h264:audio/x-ac3
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@ -153,8 +165,8 @@
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*
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* ## Loading a profile from encoding targets
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*
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* Anywhere where you have to use a string to define a #GstEncodingProfile,
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* you can use load it from a #GstEncodingTarget using the following syntaxes:
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* Anywhere you have to use a string to define a #GstEncodingProfile, you
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* can use load it from a #GstEncodingTarget using the following syntaxes:
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*
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* ```
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* target_name[/profilename/category]
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