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-<h1><font color=#000070>
-Programming with Xiphophorus <tt>libvorbis</tt>
-</font></h1>
-
-<em>Last update to this document: July 22, 1999</em><br>
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+
+<h1>Programming with Xiph.Org <tt>libvorbis</tt></h1>
<h2>Description</h2>
-Libvorbis is Xiphophorus's portable Ogg Vorbis CODEC implemented as a
-programmatic library. Libvorbis provides primitives to handle framing
-and manipulation of OggSquish bitstreams (used by the Vorbis for
-streaming), a full analysis (encoding) interface as well as packet
-decoding and synthesis for playback. <p>
+<p>Libvorbis is the Xiph.Org Foundation's portable Ogg Vorbis CODEC
+implemented as a programmatic library. Libvorbis provides primitives
+to handle framing and manipulation of Ogg bitstreams (used by the
+Vorbis for streaming), a full analysis (encoding) interface as well as
+packet decoding and synthesis for playback.</p>
-The libvorbis library does not provide any system interface; a
+<p>The libvorbis library does not provide any system interface; a
full-featured demonstration player included with the library
distribtion provides example code for a variety of system interfaces
-as well as a working example of using libvorbis in production code.
+as well as a working example of using libvorbis in production code.</p>
<h2>Encoding Overview</h2>
-
-
<h2>Decoding Overview</h2>
-Decoding a bitstream with libvorbis follows roughly the following
-steps:
+<p>Decoding a bitstream with libvorbis follows roughly the following
+steps:</p>
<ol>
-<li>Frame the incoming bitstream into pages
-<li>Sort the pages by logical bitstream and buffer then into logical streams
-<li>Decompose the logical streams into raw packets
-<li>Reconstruct segments of the original data from each packet
-<li>Glue the reconstructed segments back into a decoded stream
+<li>Frame the incoming bitstream into pages</li>
+<li>Sort the pages by logical bitstream and buffer then into logical streams</li>
+<li>Decompose the logical streams into raw packets</li>
+<li>Reconstruct segments of the original data from each packet</li>
+<li>Glue the reconstructed segments back into a decoded stream</li>
</ol>
<h3>Framing</h3>
-An OggSquish bitstream is logically arranged into pages, but to decode
-the pages, we have to find them first. The raw bitstream is first fed
+<p>An Ogg bitstream is logically arranged into pages, but to decode
+the pages, we have to find them first. The raw bitstream is first fed
into an <tt>ogg_sync_state</tt> buffer using <tt>ogg_sync_buffer()</tt>
-and <tt>ogg_sync_wrote()</tt>. After each block we submit to the sync
+and <tt>ogg_sync_wrote()</tt>. After each block we submit to the sync
buffer, we should check to see if we can frame and extract a complete
-page or pages using <tt>ogg_sync_pageout()</tt>. Extra pages are
+page or pages using <tt>ogg_sync_pageout()</tt>. Extra pages are
buffered; allowing them to build up in the <tt>ogg_sync_state</tt>
-buffer will eventually exhaust memory.<p>
+buffer will eventually exhaust memory.</p>
-The Ogg pages returned from <tt>ogg_sync_pageout</tt> need not be
+<p>The Ogg pages returned from <tt>ogg_sync_pageout</tt> need not be
decoded further to be used as landmarks in seeking; seeking can be
either a rough process of simply jumping to approximately intuited
portions of the bitstream, or it can be a precise bisection process
-that captures pages and inspects data position. When seeking,
+that captures pages and inspects data position. When seeking,
however, sequential multiplexing (chaining) must be accounted for;
beginning play in a new logical bitstream requires initializing a
-synthesis engine with the headers from that bitstream. Vorbis
-bitstreams do not make use of concurent multiplexing (grouping).<p>
+synthesis engine with the headers from that bitstream. Vorbis
+bitstreams do not make use of concurent multiplexing (grouping).</p>
<h3>Sorting</h3>
-The pages produced by <tt>ogg_sync_pageout</tt> are then sorted by
-serial number to seperate logical bitstreams. Initialize logical
+<p>The pages produced by <tt>ogg_sync_pageout</tt> are then sorted by
+serial number to seperate logical bitstreams. Initialize logical
bitstream buffers (<tt>og_stream_state</tt>) using
<tt>ogg_stream_init()</tt>. Pages are submitted to the matching
logical bitstream buffer using <tt>ogg_stream_pagein</tt>; the serial
number of the page and the stream buffer must match, or the page will
-be rejected. A page submitted out of sequence will simply be noted,
+be rejected. A page submitted out of sequence will simply be noted,
and in the course of outputting packets, the hole will be flagged
(<tt>ogg_sync_pageout</tt> and <tt>ogg_stream_packetout</tt> will
return a negative value at positions where they had to recapture the
-stream).
+stream).</p>
<h3>Extracting packets</h3>
-After submitting page[s] to a logical stream, read available packets
-using <tt>ogg_stream_packetout</tt>.
+<p>After submitting page[s] to a logical stream, read available packets
+using <tt>ogg_stream_packetout</tt>.</p>
<h3>Decoding packets</h3>
<h3>Reassembling data segments</h3>
+<h2>Ogg Bitstream Manipulation Structures</h2>
-<h2>OggSquish Bitstream Manipulation Structures</h3>
-
-Two of the OggSquish bitstream data structures are intended to be
-transparent to the developer; the fields should be used directly.<p>
+<p>Two of the Ogg bitstream data structures are intended to be
+transparent to the developer; the fields should be used directly.</p>
<h3>ogg_packet</h3>
long b_o_s;
long e_o_s;
- size64 frameno;
+ size64 granulepos;
} ogg_packet;
</pre>
<dl>
-<dt>packet: <dd>a pointer to the byte data of the raw packet
-<dt>bytes: <dd>the size of the packet' raw data
-<dt>b_o_s: <dd>beginning of stream; nonzero if this is the first packet of
- the logical bitstream
-<dt>e_o_s: <dd>end of stream; nonzero if this is the last packet of the
- logical bitstream
-<dt>frameno: <dd>the absolute position of this packet in the original
- uncompressed data stream.
+<dt>packet:</dt>
+<dd>a pointer to the byte data of the raw packet</dd>
+<dt>bytes:</dt>
+<dd>the size of the packet' raw data</dd>
+<dt>b_o_s:</dt>
+<dd>beginning of stream; nonzero if this is the first packet of
+ the logical bitstream</dd>
+<dt>e_o_s:</dt>
+<dd>end of stream; nonzero if this is the last packet of the
+ logical bitstream</dd>
+<dt>granulepos:</dt>
+<dd>the absolute position of this packet in the original
+ uncompressed data stream.</dd>
</dl>
-<h4>encoding notes</h4> The encoder is responsible for setting all of
+<h4>encoding notes</h4>
+
+<p>The encoder is responsible for setting all of
the fields of the packet to appropriate values before submission to
<tt>ogg_stream_packetin()</tt>; however, it is noted that the value in
<tt>b_o_s</tt> is ignored; the first page produced from a given
<tt>ogg_stream_state</tt> structure will be stamped as the initial
-page. <tt>e_o_s</tt>, however, must be set; this is the means by
-which the stream encoding primitives handle end of stream and cleanup.
+page. <tt>e_o_s</tt>, however, must be set; this is the means by
+which the stream encoding primitives handle end of stream and cleanup.</p>
-<h4>decoding notes</h4><tt>ogg_stream_packetout()</tt> sets the fields
-to appropriate values. Note that frameno will be >= 0 only in the
+<h4>decoding notes</h4>
+
+<p><tt>ogg_stream_packetout()</tt> sets the fields
+to appropriate values. Note that granulepos will be >= 0 only in the
case that the given packet actually represents that position (ie, only
the last packet completed on any page will have a meaningful
-<tt>frameno</tt>). Intervening frames will see <tt>frameno</tt> set
-to -1.
+<tt>granulepos</tt>). Intervening frames will see <tt>granulepos</tt> set
+to -1.</p>
<h3>ogg_page</h3>
</pre>
<dl>
-<dt>header: <dd>pointer to the page header data
-<dt>header_len: <dd>length of the page header in bytes
-<dt>body: <dd>pointer to the page body
-<dt>body_len: <dd>length of the page body
+<dt>header:</dt>
+<dd>pointer to the page header data</dd>
+<dt>header_len:</dt>
+<dd>length of the page header in bytes</dd>
+<dt>body:</dt>
+<dd>pointer to the page body</dd>
+<dt>body_len:</dt>
+<dd>length of the page body</dd>
</dl>
-Note that although the <tt>header</tt> and <tt>body</tt> pointers do
+<p>Note that although the <tt>header</tt> and <tt>body</tt> pointers do
not necessarily point into a single contiguous page vector, the page
-body must immediately follow the header in the bitstream.<p>
+body must immediately follow the header in the bitstream.</p>
-<h2>OggSquish Bitstream Manipulation Functions</h3>
+<h2>Ogg Bitstream Manipulation Functions</h2>
<h3>
int ogg_page_bos(ogg_page *og);
</h3>
-Returns the 'beginning of stream' flag for the given Ogg page. The
+<p>Returns the 'beginning of stream' flag for the given Ogg page. The
beginning of stream flag is set on the initial page of a logical
-bitstream.<P>
+bitstream.</p>
-Zero indicates the flag is cleared (this is not the initial page of a
-logical bitstream). Nonzero indicates the flag is set (this is the
-initial page of a logical bitstream).<p>
+<p>Zero indicates the flag is cleared (this is not the initial page of a
+logical bitstream). Nonzero indicates the flag is set (this is the
+initial page of a logical bitstream).</p>
<h3>
int ogg_page_continued(ogg_page *og);
</h3>
-Returns the 'packet continued' flag for the given Ogg page. The packet
+<p>Returns the 'packet continued' flag for the given Ogg page. The packet
continued flag indicates whether or not the body data of this page
-begins with packet continued from a preceeding page.<p>
-Zero (unset) indicates that the body data begins with a new packet.
+begins with packet continued from a preceeding page.</p>
+
+<p>Zero (unset) indicates that the body data begins with a new packet.
Nonzero (set) indicates that the first packet data on the page is a
-continuation from the preceeding page.
+continuation from the preceeding page.</p>
<h3>
int ogg_page_eos(ogg_page *og);
</h3>
-Returns the 'end of stream' flag for a give Ogg page. The end of page
-flag is set on the last (terminal) page of a logical bitstream.<p>
+<p>Returns the 'end of stream' flag for a give Ogg page. The end of page
+flag is set on the last (terminal) page of a logical bitstream.</p>
-Zero (unset) indicates that this is not the last page of a logical
-bitstream. Nonzero (set) indicates that this is the last page of a
+<p>Zero (unset) indicates that this is not the last page of a logical
+bitstream. Nonzero (set) indicates that this is the last page of a
logical bitstream and that no addiitonal pages belonging to this
-bitstream may follow.<p>
+bitstream may follow.</p>
<h3>
-size64 ogg_page_frameno(ogg_page *og);
+size64 ogg_page_granulepos(ogg_page *og);
</h3>
-Returns the position of this page as an absolute position within the
-original uncompressed data. The position, as returned, is 'frames
+<p>Returns the position of this page as an absolute position within the
+original uncompressed data. The position, as returned, is 'frames
encoded to date up to and including the last whole packet on this
-page'. Partial packets begun on this page but continued to the
-following page are not included. If no packet ends on this page, the
+page'. Partial packets begun on this page but continued to the
+following page are not included. If no packet ends on this page, the
frame position value will be equal to the frame position value of the
-preceeding page. If none of the original uncompressed data is yet
+preceeding page. If none of the original uncompressed data is yet
represented in the logical bitstream (for example, the first page of a
bitstream consists only of a header packet; this packet encodes only
-metadata), the value shall be zero.<p>
+metadata), the value shall be zero.</p>
-The units of the framenumber are determined by media mapping. A
+<p>The units of the framenumber are determined by media mapping. A
vorbis audio bitstream, for example, defines one frame to be the
channel values from a single sampling period (eg, a 16 bit stereo
bitstream consists of two samples of two bytes for a total of four
-bytes, thus a frame would be four bytes). A video stream defines one
-frame to be a single frame of video.<p>
+bytes, thus a frame would be four bytes). A video stream defines one
+frame to be a single frame of video.</p>
<h3>
int ogg_page_pageno(ogg_page *og);
</h3>
-Returns the sequential page number of the given Ogg page. The first
+<p>Returns the sequential page number of the given Ogg page. The first
page in a logical bitstream is numbered zero; following pages are
-numbered in increasing monotonic order.<p>
+numbered in increasing monotonic order.</p>
<h3>
int ogg_page_serialno(ogg_page *og);
</h3>
-Returns the serial number of the given Ogg page. The serial number is
+<p>Returns the serial number of the given Ogg page. The serial number is
used as a handle to distinguish various logical bitstreams in a
-physical OggSquish bitstresm. Every logical bitstream within a
+physical Ogg bitstresm. Every logical bitstream within a
physical bitstream must use a unique (within the scope of the physical
-bitstream) serial number, which is stamped on all bitstream pages.<p>
+bitstream) serial number, which is stamped on all bitstream pages.</p>
<h3>
int ogg_page_version(ogg_page *og);
</h3>
-Returns the revision of the Ogg bitstream structure of the given page.
-Currently, the only permitted number is zero. Later revisions of the
+<p>Returns the revision of the Ogg bitstream structure of the given page.
+Currently, the only permitted number is zero. Later revisions of the
bitstream spec will increment this version should any changes be
incompatable.</p>
int ogg_stream_clear(ogg_stream_state *os);
</h3>
-Clears and deallocates the internal storage of the given Ogg stream.
+<p>Clears and deallocates the internal storage of the given Ogg stream.
After clearing, the stream structure is not initialized for use;
<tt>ogg_stream_init</tt> must be called to reinitialize for use.
Use <tt>ogg_stream_reset</tt> to reset the stream state
-to a fresh, intiialized state.<p>
+to a fresh, intiialized state.</p>
-<tt>ogg_stream_clear</tt> does not call <tt>free()</tt> on the pointer
+<p><tt>ogg_stream_clear</tt> does not call <tt>free()</tt> on the pointer
<tt>os</tt>, allowing use of this call on stream structures in static
-or automatic storage. <tt>ogg_stream_destroy</tt>is a complimentary
-function that frees the pointer as well.<p>
+or automatic storage. <tt>ogg_stream_destroy</tt>is a complimentary
+function that frees the pointer as well.</p>
-Returns zero on success and non-zero on failure. This function always
-succeeds.<p>
+<p>Returns zero on success and non-zero on failure. This function always
+succeeds.</p>
<h3>
int ogg_stream_destroy(ogg_stream_state *os);
</h3>
-Clears and deallocates the internal storage of the given Ogg stream,
-then frees the storage associated with the pointer <tt>os</tt>.<p>
+<p>Clears and deallocates the internal storage of the given Ogg stream,
+then frees the storage associated with the pointer <tt>os</tt>.</p>
-<tt>ogg_stream_clear</tt> does not call <tt>free()</tt> on the pointer
+<p><tt>ogg_stream_clear</tt> does not call <tt>free()</tt> on the pointer
<tt>os</tt>, allowing use of that call on stream structures in static
-or automatic storage.<p>
+or automatic storage.</p>
-Returns zero on success and non-zero on failure. This function always
-succeeds.<p>
+<p>Returns zero on success and non-zero on failure. This function always
+succeeds.</p>
<h3>
int ogg_stream_init(ogg_stream_state *os,int serialno);
</h3>
-Initialize the storage associated with <tt>os</tt> for use as an Ogg
-stream. This call is used to initialize a stream for both encode and
-decode. The given serial number is the serial number that will be
+<p>Initialize the storage associated with <tt>os</tt> for use as an Ogg
+stream. This call is used to initialize a stream for both encode and
+decode. The given serial number is the serial number that will be
stamped on pages of the produced bitstream (during encode), or used as
-a check that pages match (during decode).<p>
+a check that pages match (during decode).</p>
-Returns zero on success, nonzero on failure.<p>
+<p>Returns zero on success, nonzero on failure.</p>
<h3>
int ogg_stream_packetin(ogg_stream_state *os, ogg_packet *op);
</h3>
-Used during encoding to add the given raw packet to the given Ogg
-bitstream. The contents of <tt>op</tt> are copied;
+<p>Used during encoding to add the given raw packet to the given Ogg
+bitstream. The contents of <tt>op</tt> are copied;
<tt>ogg_stream_packetin</tt> does not retain any pointers into
<tt>op</tt>'s storage. The encoding proccess buffers incoming packets
until enough packets have been assembled to form an entire page;
-<tt>ogg_stream_pageout</tt> is used to read complete pages.<p>
+<tt>ogg_stream_pageout</tt> is used to read complete pages.</p>
-Returns zero on success, nonzero on failure.<p>
+<p>Returns zero on success, nonzero on failure.</p>
<h3>
int ogg_stream_packetout(ogg_stream_state *os,ogg_packet *op);
</h3>
-Used during decoding to read raw packets from the given logical
-bitstream. <tt>ogg_stream_packetout</tt> will only return complete
-packets for which checksumming indicates no corruption. The size and
+<p>Used during decoding to read raw packets from the given logical
+bitstream. <tt>ogg_stream_packetout</tt> will only return complete
+packets for which checksumming indicates no corruption. The size and
contents of the packet exactly match those given in the encoding
-process. <p>
+process. </p>
-Returns zero if the next packet is not ready to be read (not buffered
+<p>Returns zero if the next packet is not ready to be read (not buffered
or incomplete), positive if it returned a complete packet in
<tt>op</tt> and negative if there is a gap, extra bytes or corruption
at this position in the bitstream (essentially that the bitstream had
-to be recaptured). A negative value is not necessarily an error. It
+to be recaptured). A negative value is not necessarily an error. It
would be a common occurence when seeking, for example, which requires
-recapture of the bitstream at the position decoding continued.<p>
+recapture of the bitstream at the position decoding continued.</p>
-Iff the return value is positive, <tt>ogg_stream_packetout</tt> placed
-a packet in <tt>op</tt>. The data in <t>op</tt> points to static
+<p>If the return value is positive, <tt>ogg_stream_packetout</tt> placed
+a packet in <tt>op</tt>. The data in <tt>op</tt> points to static
storage that is valid until the next call to
<tt>ogg_stream_pagein</tt>, <tt>ogg_stream_clear</tt>,
-<tt>ogg_stream_reset</tt>, or <tt>ogg_stream_destroy</tt>. The
+<tt>ogg_stream_reset</tt>, or <tt>ogg_stream_destroy</tt>. The
pointers are not invalidated by more calls to
-<tt>ogg_stream_packetout</tt>.<p>
+<tt>ogg_stream_packetout</tt>.</p>
<h3>
int ogg_stream_pagein(ogg_stream_state *os, ogg_page *og);
</h3>
-Used during decoding to buffer the given complete, pre-verified page
+<p>Used during decoding to buffer the given complete, pre-verified page
for decoding into raw Ogg packets. The given page must be framed,
normally produced by <tt>ogg_sync_pageout</tt>, and from the logical
bitstream associated with <tt>os</tt> (the serial numbers must match).
The contents of the given page are copied; <tt>ogg_stream_pagein</tt>
-retains no pointers into <tt>og</tt> storage.<p>
+retains no pointers into <tt>og</tt> storage.</p>
-Returns zero on success and non-zero on failure.<p>
+<p>Returns zero on success and non-zero on failure.</p>
<h3>
int ogg_stream_pageout(ogg_stream_state *os, ogg_page *og);
</h3>
-Used during encode to read complete pages from the stream buffer. The
-returned page is ready for sending out to the real world.<p>
+<p>Used during encode to read complete pages from the stream buffer. The
+returned page is ready for sending out to the real world.</p>
-Returns zero if there is no complete page ready for reading. Returns
+<p>Returns zero if there is no complete page ready for reading. Returns
nonzero when it has placed data for a complete page into
<tt>og</tt>. Note that the storage returned in og points into internal
storage; the pointers in <tt>og</tt> are valid until the next call to
<tt>ogg_stream_pageout</tt>, <tt>ogg_stream_packetin</tt>,
<tt>ogg_stream_reset</tt>, <tt>ogg_stream_clear</tt> or
-<tt>ogg_stream_destroy</tt>.
+<tt>ogg_stream_destroy</tt>.</p>
<h3>
int ogg_stream_reset(ogg_stream_state *os);
</h3>
-Resets the given stream's state to that of a blank, unused stream;
-this may be used during encode or decode. <p>
+<p>Resets the given stream's state to that of a blank, unused stream;
+this may be used during encode or decode.</p>
-Note that if used during encode, it does not alter the stream's serial
-number. In addition, the next page produced during encoding will be
-marked as the 'initial' page of the logical bitstream.<p>
+<p>Note that if used during encode, it does not alter the stream's serial
+number. In addition, the next page produced during encoding will be
+marked as the 'initial' page of the logical bitstream.</p>
-When used during decode, this simply clears the data buffer of any
-pending pages. Beginning and end of stream cues are read from the
-bitstream and are unaffected by reset.<p>
+<p>When used during decode, this simply clears the data buffer of any
+pending pages. Beginning and end of stream cues are read from the
+bitstream and are unaffected by reset.</p>
-Returns zero on success and non-zero on failure. This function always
-succeeds.<p>
+<p>Returns zero on success and non-zero on failure. This function always
+succeeds.</p>
<h3>
char *ogg_sync_buffer(ogg_sync_state *oy, long size);
</h3>
-This call is used to buffer a raw bitstream for framing and
+<p>This call is used to buffer a raw bitstream for framing and
verification. <tt>ogg_sync_buffer</tt> handles stream capture and
recapture, checksumming, and division into Ogg pages (as required by
-<tt>ogg_stream_pagein</tt>).<p>
+<tt>ogg_stream_pagein</tt>).</p>
-<tt>ogg_sync_buffer</tt> exposes a buffer area into which the decoder
-copies the next (up to) <tt>size</tt> bytes. We expose the buffer
+<p><tt>ogg_sync_buffer</tt> exposes a buffer area into which the decoder
+copies the next (up to) <tt>size</tt> bytes. We expose the buffer
(rather than taking a buffer) in order to avoid an extra copy many
uses; this way, for example, <tt>read()</tt> can transfer data
directly into the stream buffer without first needing to place it in
-temporary storage.<p>
+temporary storage.</p>
-Returns a pointer into <tt>oy</tt>'s internal bitstream sync buffer;
+<p>Returns a pointer into <tt>oy</tt>'s internal bitstream sync buffer;
the remaining space in the sync buffer is at least <tt>size</tt>
-bytes. The decoder need not write all of <tt>size</tt> bytes;
+bytes. The decoder need not write all of <tt>size</tt> bytes;
<tt>ogg_sync_wrote</tt> is used to inform the engine how many bytes
were actually written. Use of <tt>ogg_sync_wrote</tt> after writing
-into the exposed buffer is mandantory.<p>
+into the exposed buffer is mandantory.</p>
<h3>
int ogg_sync_clear(ogg_sync_state *oy);
</h3>
-<tt>ogg_sync_clear</tt>
-
-Clears and deallocates the internal storage of the given Ogg sync
-buffer. After clearing, the sync structure is not initialized for
+<p><tt>ogg_sync_clear</tt>
+clears and deallocates the internal storage of the given Ogg sync
+buffer. After clearing, the sync structure is not initialized for
use; <tt>ogg_sync_init</tt> must be called to reinitialize for use.
Use <tt>ogg_sync_reset</tt> to reset the sync state and buffer to a
-fresh, intiialized state.<p>
+fresh, intiialized state.</p>
-<tt>ogg_sync_clear</tt> does not call <tt>free()</tt> on the pointer
+<p><tt>ogg_sync_clear</tt> does not call <tt>free()</tt> on the pointer
<tt>oy</tt>, allowing use of this call on sync structures in static
-or automatic storage. <tt>ogg_sync_destroy</tt>is a complimentary
-function that frees the pointer as well.<p>
+or automatic storage. <tt>ogg_sync_destroy</tt>is a complimentary
+function that frees the pointer as well.</p>
-Returns zero on success and non-zero on failure. This function always
-succeeds.<p>
+<p>Returns zero on success and non-zero on failure. This function always
+succeeds.</p>
<h3>
int ogg_sync_destroy(ogg_sync_state *oy);
</h3>
-Clears and deallocates the internal storage of the given Ogg sync
+<p>Clears and deallocates the internal storage of the given Ogg sync
buffer, then frees the storage associated with the pointer
-<tt>oy</tt>.<p>
+<tt>oy</tt>.</p>
-<tt>ogg_sync_clear</tt> does not call <tt>free()</tt> on the pointer
-<tt>oy</tt>, allowing use of that call on stream structures in static
-or automatic storage.<p>
+<p>An alternative function,<tt>ogg_sync_clear</tt>, does not call
+<tt>free()</tt> on the pointer <tt>oy</tt>, allowing use of that call on
+stream structures in static or automatic storage.</p>
-Returns zero on success and non-zero on failure. This function always
-succeeds.<p>
+<p>Returns zero on success and non-zero on failure. This function always
+succeeds.</p>
<h3>
int ogg_sync_init(ogg_sync_state *oy);
</h3>
-Initializes the sync buffer <tt>oy</tt> for use.<p>
-Returns zero on success and non-zero on failure. This function always
-succeeds.<p>
+<p>Initializes the sync buffer <tt>oy</tt> for use.</p>
+
+<p>Returns zero on success and non-zero on failure. This function always
+succeeds.</p>
<h3>
int ogg_sync_pageout(ogg_sync_state *oy, ogg_page *og);
</h3>
-Reads complete, framed, verified Ogg pages from the sync buffer,
-placing the page data in <tt>og</tt>.<p>
+<p>Reads complete, framed, verified Ogg pages from the sync buffer,
+placing the page data in <tt>og</tt>.</p>
-Returns zero when there's no complete pages buffered for
+<p>Returns zero when there's no complete pages buffered for
retrieval. Returns negative when a loss of sync or recapture occurred
(this is not necessarily an error; recapture would be required after
-seeking, for example). Returns positive when a page is returned in
+seeking, for example). Returns positive when a page is returned in
<tt>og</tt>. Note that the data in <tt>og</tt> points into the sync
buffer storage; the pointers are valid until the next call to
<tt>ogg_sync_buffer</tt>, <tt>ogg_sync_clear</tt>,
-<tt>ogg_sync_destroy</tt> or <tt>ogg_sync_reset</tt>.
-
+<tt>ogg_sync_destroy</tt> or <tt>ogg_sync_reset</tt>.</p>
<h3>
int ogg_sync_reset(ogg_sync_state *oy);
</h3>
-<tt>ogg_sync_reset</tt> resets the sync state in <tt>oy</tt> to a
-clean, empty state. This is useful, for example, when seeking to a
-new location in a bitstream.<p>
+<p><tt>ogg_sync_reset</tt> resets the sync state in <tt>oy</tt> to a
+clean, empty state. This is useful, for example, when seeking to a
+new location in a bitstream.</p>
-Returns zero on success, nonzero on failure.<p>
+<p>Returns zero on success, nonzero on failure.</p>
<h3>
int ogg_sync_wrote(ogg_sync_state *oy, long bytes);
</h3>
-Used to inform the sync state as to how many bytes were actually
-written into the exposed sync buffer. It must be equal to or less
-than the size of the buffer requested.<p>
-
-Returns zero on success and non-zero on failure; failure occurs only
-when the number of bytes written were larger than the buffer.<p>
-
-<hr>
-<a href="http://www.xiph.org/">
-<img src="white-xifish.gif" align=left border=0>
-</a>
-<font size=-2 color=#505050>
-
-OggSquish is a <a href="http://www.xiph.org">Xiphophorus</a> effort to
-protect essential tenets of Internet multimedia from corporate
-hostage-taking; Open Source is the net's greatest tool to keep
-everyone honest. See <a href="http://www.xiph.org/about.html">About
-Xiphophorus</a> for details.
-<p>
-
-Ogg Vorbis is the first OggSquish audio CODEC. Anyone may
-freely use and distribute the OggSquish and Vorbis specification,
-whether in a private, public or corporate capacity. However,
-Xiphophorus and the Ogg project (xiph.org) reserve the right to set
-the Ogg/Vorbis specification and certify specification compliance.<p>
-
-Xiphophorus's Vorbis software CODEC implementation (libvorbis and the
-vorbis encode/decode/playback utility) are distributed under the GNU
-Public License. This does not restrict third parties from
-distributing independent implementations of Vorbis software under
-other licenses.<p>
-
-OggSquish, Vorbis, Xiphophorus and their logos are trademarks (tm) of
-<a href="http://www.xiph.org/">Xiphophorus</a>. These pages are
-copyright (C) 1994-1999 Xiphophorus. All rights reserved.<p>
-
-</body>
-
-
+<p>Used to inform the sync state as to how many bytes were actually
+written into the exposed sync buffer. It must be equal to or less
+than the size of the buffer requested.</p>
+<p>Returns zero on success and non-zero on failure; failure occurs only
+when the number of bytes written were larger than the buffer.</p>
+<div id="copyright">
+ The Xiph Fish Logo is a
+ trademark (™) of Xiph.Org.<br/>
+ These pages © 1994 - 2005 Xiph.Org. All rights reserved.
+</div>
+</body>
+</html>
projects / platform / upstream / libvorbis.git / blobdiff