156 lines
4.0 KiB
Racket
156 lines
4.0 KiB
Racket
#lang scribble/manual
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@(require
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(for-label
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racket/base
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(file "../didl-lite.rkt")
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(file "../media-file-server.rkt")))
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@title{Publishing Media Files}
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@defmodule[(file "../media-file-server.rkt")]
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This module publishes local files through a small Racket web server. The
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underlying Racket file dispatcher streams files and supports both @tt{HEAD}
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requests and HTTP byte ranges. Byte ranges are important for media-renderer
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probing and seeking.
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@defproc[(start-media-file-server
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[url string?]
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[#:listen-ip listen-ip (or/c #f string?) #f])
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media-file-server?]{
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Starts a server for the HTTP origin and path prefix in @racket[url].
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The URL must be an absolute @tt{http://} URL. A trailing slash is added when
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needed.
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When @racket[listen-ip] is @racket[#f], the server listens on all local
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interfaces. Supply a local address, such as @tt{10.7.3.118}, to restrict the
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listener to that interface.
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}
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@defproc[(media-file-server-url
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[server media-file-server?])
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string?]{
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Returns the normalized base URL of @racket[server].
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}
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@defproc[(media-file-server-publish!
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[server media-file-server?]
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[file path-string?]
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[url string?]
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[#:mime-type mime-type (or/c #f bytes? string?) #f])
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string?]{
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Publishes @racket[file] at @racket[url] and returns the absolute URL.
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The URL may be relative to the server URL:
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@racketblock[
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(define uri
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(media-file-server-publish!
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files
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"C:/muziek/test.flac"
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"test.flac"))
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]
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It may also be the complete URL, provided that its origin and path prefix match
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the server:
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@racketblock[
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(media-file-server-publish!
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files
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"C:/muziek/test.flac"
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"http://10.7.3.118:8080/media/test.flac")
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]
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The MIME type is inferred for common audio, video, and image extensions.
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Use @racket[#:mime-type] to override it.
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}
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@defproc[(media-file-server-unpublish!
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[server media-file-server?]
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[url string?])
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void?]{
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Removes the URL mapping. Requests that are already in progress may still
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finish.
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}
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@defproc[(media-file-server-didl-lite
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[server media-file-server?]
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[url string?]
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[#:title title (or/c #f string?) #f]
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[#:artist artist (or/c #f string?) #f]
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[#:album album (or/c #f string?) #f]
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[#:genre genre (or/c #f string?) #f]
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[#:year year (or/c #f exact-nonnegative-integer?) #f]
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[#:track track (or/c #f exact-nonnegative-integer?) #f]
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[#:duration duration (or/c #f nonnegative-real?) #f]
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[#:id id string? "0"]
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[#:parent-id parent-id string? "0"])
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string?]{
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Returns DIDL-Lite metadata for a URL previously installed with
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@racket[media-file-server-publish!]. The MIME type, file size, and
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@tt{DLNA.ORG_OP=01} byte-range capability are taken from the actual
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publication. The file name is used as the title when @racket[title] is
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@racket[#f].
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Pass the result as @racket[#:metadata] or @racket[#:next-metadata] to the
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media-renderer functions. Supplying the duration is recommended because some
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renderers use it when deciding whether time seeking is available.
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}
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@defproc[(media-file-server-stop!
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[server media-file-server?])
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void?]{
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Stops the web server. Repeated calls have no effect.
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}
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@section{Playing local files}
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@racketblock[
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(define files
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(start-media-file-server
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"http://10.7.3.118:8080/media/"
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#:listen-ip "10.7.3.118"))
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(define first-uri
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(media-file-server-publish!
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files
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"C:/muziek/first.flac"
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"first.flac"))
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(define second-uri
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(media-file-server-publish!
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files
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"C:/muziek/second.flac"
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"second.flac"))
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(define first-metadata
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(media-file-server-didl-lite
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files
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first-uri
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#:title "First track"
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#:duration 639))
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(define second-metadata
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(media-file-server-didl-lite
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files
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second-uri
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#:title "Second track"
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#:duration 242))
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(media-renderer-play-uri!
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renderer
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first-uri
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#:metadata first-metadata
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#:next-uri second-uri
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#:next-metadata second-metadata)
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]
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Keep the URLs published until the renderer has finished reading them.
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