Vigith Maurice > Ogg-LibOgg-0.02 > Ogg::LibOgg

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NAME ^

Ogg::LibOgg - XS Code for Ogg bindings for Perl.

SYNOPSIS ^

  use Ogg::LibOgg;
  my $filename = "t/test.ogg";
  open $fd, $filename or die "Can't open $filename: $!";
  ## Make Ogg Packet
  my $op = Ogg::LibOgg::make_ogg_packet();
  ## Make Ogg Stream State
  my $os = Ogg::LibOgg::make_ogg_stream_state();
  ## Make Ogg Page
  my $og = Ogg::LibOgg::make_ogg_page();
  ## Make Ogg Sync State
  my $oy = Ogg::LibOgg::make_ogg_sync_state();
  ## Ogg Sync Init
  Ogg::LibOgg::ogg_sync_init($oy); # this should be == 0
  ## Ogg Read Page (this is a custom wrapper, please read the perldoc)
  Ogg::LibOgg::ogg_read_page($fd, $oy, $og); # == 0, 
  ## Ogg Page Serial Number
  my $slno = Ogg::LibOgg::ogg_page_serialno($og);
  ..etc..
  close $fd;

DESCRIPTION ^

Ogg::LibOgg let you call the libogg functions directly and the glue is written in XS. Please read LibOgg.xs to understand the implementation.

EXPORT

None by default. Please use Ogg::LibOgg ':all' to export everything to the current namespace.

Functions (malloc) ^

Memory Allocation for the Ogg Structures

make_ogg_packet

Creates an Ogg Packet.

-Input: Void

-Output: Memory address of Ogg Packet.

make_ogg_stream_state

Creates an Ogg Stream State.

-Input: Void

-Output: Memory address of Ogg Stream State.

make_ogg_page

Creates an Ogg Page.

-Input: Void

-Output: Memory address of Ogg Page.

make_ogg_sync_state

Creates an Ogg Sync State.

-Input: Void

-Output: Memory address og Ogg Sync State.

Functions (Bitstream Primitives) ^

ogg_stream_init

This function is used to initialize an ogg_stream_state struct and allocates appropriate memory in preparation for encoding or decoding. http://www.xiph.org/ogg/doc/libogg/ogg_stream_init.html

-Input: ogg_stream_state (memory addr) serial number

-Output: 0 if successful -1 if unsuccessful

ogg_read_page

This function is a wrapper around ogg_sync_pageout. In an actual decoding loop, this function should be called first to ensure that the buffer is cleared. The example code below illustrates a clean reading loop which will fill and output pages.

ogg_sync_pageout takes the data stored in the buffer of the ogg_sync_state struct and inserts them into an ogg_page.

  if (ogg_sync_pageout(&oy, &og) != 1) {
        buffer = ogg_sync_buffer(&oy, 8192);
        bytes = fread(buffer, 1, 8192, stdin);
        ogg_sync_wrote(&oy, bytes);
  }

-Input: FILE * ogg_sync_state ogg_page

-Output: -1 buffer overflow or internal error (status of ogg_sync_wrote) 0 all other cases

ogg_page_bos

Indicates whether this page is at the beginning of the logical bitstream. http://www.xiph.org/ogg/doc/libogg/ogg_page_bos.html

-Input: ogg_page

-Output: > 0 if this page is the beginning of a bitstream. 0 if this page is from any other location in the stream.

ogg_page_eos

Indicates whether this page is at the end of the logical bitstream. http://www.xiph.org/ogg/doc/libogg/ogg_page_eos.html

-Input: ogg_page

-Output: > 0 if this page is the beginning of a bitstream. 0 if this page is from any other location in the stream.

ogg_page_checksum_set

Checksums an ogg_page. http://www.xiph.org/ogg/doc/libogg/ogg_page_checksum_set.html

(Not *SURE* why in the ogg official doc, they have given the function definition as 'int ogg_page_checksum_set(og)', it should be actuall 'void ogg_page_checksum_set(og)').

-Input: ogg_page

-Output: void

ogg_page_continued

Indicates whether this page contains packet data which has been continued from the previous page. http://www.xiph.org/ogg/doc/libogg/ogg_page_continued.html

-Input: ogg_page

-Output: int

ogg_page_granulepos

Returns the exact granular position of the packet data contained at the end of this page. http://www.xiph.org/ogg/doc/libogg/ogg_page_granulepos.html

-Input: ogg_page

-Output: n is the specific last granular position of the decoded data contained in the page.

ogg_page_packets

Returns the number of packets that are completed on this page.

http://www.xiph.org/ogg/doc/libogg/ogg_page_packets.html

-Input: ogg_page

-Output: 1 If a page consists of a packet begun on a previous page, != 0 a new packet begun (but not completed) on this page,

  0 If a page happens to be a single packet that was begun on a previous page, 
  != 0 and spans to the next page

ogg_page_pageno

Returns the sequential page number. http://www.xiph.org/ogg/doc/libogg/ogg_page_pageno.html

-Input: ogg_page

-Output: n, is the page number for this page.

ogg_page_serialno

Returns the unique serial number for the logical bitstream of this page. Each page contains the serial number for the logical bitstream that it belongs to. http://www.xiph.org/ogg/doc/libogg/ogg_page_serialno.html

-Input: ogg_page

-Output: n, where n is the serial number for this page.

ogg_stream_clear

This function clears and frees the internal memory used by the ogg_stream_state struct, but does not free the structure itself. http://www.xiph.org/ogg/doc/libogg/ogg_stream_clear.html

-Input: ogg_stream_state

-Output: 0 is always returned

ogg_stream_reset

This function sets values in the ogg_stream_state struct back to initial values. http://www.xiph.org/ogg/doc/libogg/ogg_stream_reset.html

-Input: ogg_stream_state

-Output: 0, success != 0, internal error

ogg_stream_reset_serialno

Similar to ogg_stream_reset, but it also it sets the stream serial number to the given value. http://www.xiph.org/ogg/doc/libogg/ogg_stream_reset_serialno.html

-Input: ogg_stream_state serialno

-Output: 0, success != 0, internal error

ogg_stream_destroy

This function frees the internal memory used by the ogg_stream_state struct as well as the structure itself. http://www.xiph.org/ogg/doc/libogg/ogg_stream_destroy.html

-Input: ogg_stream_state

-Output: 0, always

ogg_stream_check

This function is used to check the error or readiness condition of an ogg_stream_state structure. http://www.xiph.org/ogg/doc/libogg/ogg_stream_check.html

-Input: ogg_stream_state

-Output: 0, if the ogg_stream_state structure is initialized and ready. != 0, never initialized, or if an unrecoverable internal error occurred

ogg_page_version

This function returns the version of ogg_page used in this page. http://www.xiph.org/ogg/doc/libogg/ogg_page_version.html

-Input: ogg_page

-Output: n, is the version number (for current ogg, 0 is always returned, else error)

ogg_packet_clear

his function clears the memory used by the ogg_packet struct, but does not free the structure itself. Don't call it directly. http://www.xiph.org/ogg/doc/libogg/ogg_packet_clear.html

-Input: ogg_packet

@Ouput: void

Functions (Encoding) ^

ogg_stream_packetin

This function submits a packet to the bitstream for page encapsulation. After this is called, more packets can be submitted, or pages can be written out. http://www.xiph.org/ogg/doc/libogg/ogg_stream_packetin.html

-Input: ogg_stream_state ogg_packet

-Output: 0, on success -1, on internal error

ogg_stream_pageout

This function forms packets into pages, this would be called after using ogg_stream_packetin(). http://www.xiph.org/ogg/doc/libogg/ogg_stream_pageout.html

-Input: ogg_stream_state ogg_page

-Output: 0, insufficient data or internal error != 0, page has been completed and returned.

ogg_stream_flush

This function checks for remaining packets inside the stream and forces remaining packets into a page, regardless of the size of the page. http://www.xiph.org/ogg/doc/libogg/ogg_stream_flush.html

-Input: ogg_stream_state ogg_page

-Output: 0, means that all packet data has already been flushed into pages != 0, means that remaining packets have successfully been flushed into the page.

Functions (Decoding) ^

ogg_sync_init

ogg sync init, This function is used to initialize an ogg_sync_state struct to a known initial value in preparation for manipulation of an Ogg bitstream. http://www.xiph.org/ogg/doc/libogg/ogg_sync_init.html

-Input: ogg_sync_state (memory addr)

-Output: 0 (always)

ogg_sync_clear

This function is used to free the internal storage of an ogg_sync_state struct and resets the struct to the initial state. http://www.xiph.org/ogg/doc/libogg/ogg_sync_clear.html

-Input: ogg_sync_state

-Output: 0, always

ogg_sync_reset

This function is used to reset the internal counters of the ogg_sync_state struct to initial values. http://www.xiph.org/ogg/doc/libogg/ogg_sync_reset.html

-Input: ogg_sync_state

-Output: 0, always

ogg_sync_destroy

This function is used to destroy an ogg_sync_state struct and free all memory used. http://www.xiph.org/ogg/doc/libogg/ogg_sync_destroy.html

-Input: ogg_sync_state

@Ouput: 0, always

ogg_sync_check

This function is used to check the error or readiness condition of an ogg_sync_state structure. http://www.xiph.org/ogg/doc/libogg/ogg_sync_check.html

-Input: ogg_sync_state

-Output: 0, is returned if the ogg_sync_state structure is initialized and ready. != 0, if the structure was never initialized, or if an unrecoverable internal error

ogg_sync_buffer

This function is used to provide a properly-sized buffer for writing. http://www.xiph.org/ogg/doc/libogg/ogg_sync_buffer.html

-Input: ogg_sync_state size

-Output: Returns a pointer to the newly allocated buffer or NULL on error

ogg_sync_wrote

This function is used to tell the ogg_sync_state struct how many bytes we wrote into the buffer. http://www.xiph.org/ogg/doc/libogg/ogg_sync_wrote.html

-Input: ogg_sync_state bytes

-Output: -1 if the number of bytes written overflows the internal storage of the ogg_sync_state struct or an internal error occurred. 0 in all other cases.

ogg_sync_pageseek

This function synchronizes the ogg_sync_state struct to the next ogg_page. http://www.xiph.org/ogg/doc/libogg/ogg_sync_pageseek.html

-Input: ogg_sync_state ogg_page

-Output: -n means that we skipped n bytes within the bitstream. 0 means that we need more data, or than an internal error occurred. n means that the page was synced at the current location, with a page length of n bytes.

ogg_sync_pageout

This function takes the data stored in the buffer of the ogg_sync_state struct and inserts them into an ogg_page. In an actual decoding loop, this function should be called first to ensure that the buffer is cleared. http://www.xiph.org/ogg/doc/libogg/ogg_sync_pageout.html

-Input: ogg_sync_state ogg_page

-Output: -1 returned if stream has not yet captured sync (bytes were skipped). 0 returned if more data needed or an internal error occurred. 1 indicated a page was synced and returned.

ogg_stream_pagein

This function adds a complete page to the bitstream. In a typical decoding situation, this function would be called after using ogg_sync_pageout to create a valid ogg_page struct. http://www.xiph.org/ogg/doc/libogg/ogg_stream_pagein.html

-Input: ogg_stream_state ogg_page

-Output: -1 indicates failure. 0 means that the page was successfully submitted to the bitstream.

ogg_stream_packetout

This function assembles a data packet for output to the codec decoding engine. The data has already been submitted to the ogg_stream_state and broken into segments. Each successive call returns the next complete packet built from those segments. http://www.xiph.org/ogg/doc/libogg/ogg_stream_packetout.html

-Input: ogg_stream_state ogg_packet

-Output: -1 if we are out of sync and there is a gap in the data. 0 insufficient data available to complete a packet, or unrecoverable internal error occurred. 1 if a packet was assembled normally. op contains the next packet from the stream.

ogg_stream_packetpeek

This function attempts to assemble a raw data packet and returns it without advancing decoding. http://www.xiph.org/ogg/doc/libogg/ogg_stream_packetpeek.html

-Input: ogg_stream_state ogg_packet

-Output: -1, no packet available due to lost sync or a hole in the data. 0, insufficient data available to complete a packet, or on unrecoverable internal error 1, packet is available

CAVEATS ^

ogg_page and ogg_packet structs mostly point to storage in libvorbis/libtheora. They're never freed or manipulated directly. You may get a malloc error doing so.

oggpack_buffer struct which is used with libogg's bitpacking functions is not exposed, as you should never need to directly access anything in this structure. So are the functions manipulating oggpack_buffer, they too are not exposed. http://www.xiph.org/ogg/doc/libogg/oggpack_buffer.html

ogg_stream_iovecin, not implemented as this function submits packet data (in the form of an array of ogg_iovec_t, rather than using an ogg_packet structure) to the bitstream for page encapsulation. http://www.xiph.org/ogg/doc/libogg/ogg_stream_iovecin.html

AUTHORS ^

Vigith Maurice <vigith@yahoo-inc.com> www.vigith.com

COPYRIGHT ^

Vigith Maurice (C) 2011

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.9 or, at your option, any later version of Perl 5 you may have available.

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