ogg.c

video linux conference

/*****************************************************************************
 * ogg.c : ogg stream demux module for vlc
 *****************************************************************************
 * Copyright (C) 2001-2003 VideoLAN
 * $Id: ogg.c 11054 2005-05-18 10:23:37Z gbazin $
 *
 * Authors: Gildas Bazin <[e-mail]>
 *          Andre Pang <[e-mail]> (Annodex support)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
 *****************************************************************************/

/*****************************************************************************
 * Preamble
 *****************************************************************************/
#include <vlc/vlc.h>
#include <vlc/input.h>

#include <ogg/ogg.h>

#include "codecs.h"
#include "vlc_bits.h"

/*****************************************************************************
 * Module descriptor
 *****************************************************************************/
static int  Open ( vlc_object_t * );
static void Close( vlc_object_t * );

vlc_module_begin();
    set_description( _("Ogg stream demuxer" ) );
    set_category( CAT_INPUT );
    set_subcategory( SUBCAT_INPUT_DEMUX );
    set_capability( "demux2", 50 );
    set_callbacks( Open, Close );
    add_shortcut( "ogg" );
vlc_module_end();


/*****************************************************************************
 * Definitions of structures and functions used by this plugins
 *****************************************************************************/
typedef struct logical_stream_s
{
    ogg_stream_state os;                        /* logical stream of packets */

    es_format_t      fmt;
    es_out_id_t      *p_es;
    double           f_rate;

    int              i_serial_no;

    /* the header of some logical streams (eg vorbis) contain essential
     * data for the decoder. We back them up here in case we need to re-feed
     * them to the decoder. */
    int              b_force_backup;
    int              i_packets_backup;
    uint8_t          *p_headers;
    int              i_headers;

    /* program clock reference (in units of 90kHz) derived from the previous
     * granulepos */
    mtime_t          i_pcr;
    mtime_t          i_interpolated_pcr;
    mtime_t          i_previous_pcr;

    /* Misc */
    int b_reinit;
    int i_theora_keyframe_granule_shift;

    /* for Annodex logical bitstreams */
    int secondary_header_packets;

} logical_stream_t;

struct demux_sys_t
{
    ogg_sync_state oy;        /* sync and verify incoming physical bitstream */

    int i_streams;                           /* number of logical bitstreams */
    logical_stream_t **pp_stream;  /* pointer to an array of logical streams */

    /* program clock reference (in units of 90kHz) derived from the pcr of
     * the sub-streams */
    mtime_t i_pcr;

    /* stream state */
    int     i_eos;

    /* bitrate */
    int     i_bitrate;
};

/* OggDS headers for the new header format (used in ogm files) */
typedef struct stream_header_video
{
    ogg_int32_t width;
    ogg_int32_t height;
} stream_header_video;

typedef struct stream_header_audio
{
    ogg_int16_t channels;
    ogg_int16_t blockalign;
    ogg_int32_t avgbytespersec;
} stream_header_audio;

typedef struct stream_header
{
    char        streamtype[8];
    char        subtype[4];

    ogg_int32_t size;                               /* size of the structure */

    ogg_int64_t time_unit;                              /* in reference time */
    ogg_int64_t samples_per_unit;
    ogg_int32_t default_len;                                /* in media time */

    ogg_int32_t buffersize;
    ogg_int16_t bits_per_sample;

    union
    {
        /* Video specific */
        stream_header_video video;
        /* Audio specific */
        stream_header_audio audio;
    } sh;
} stream_header;

#define OGG_BLOCK_SIZE 4096

/* Some defines from OggDS */
#define PACKET_TYPE_HEADER   0x01
#define PACKET_TYPE_BITS     0x07
#define PACKET_LEN_BITS01    0xc0
#define PACKET_LEN_BITS2     0x02
#define PACKET_IS_SYNCPOINT  0x08

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
static int  Demux  ( demux_t * );
static int  Control( demux_t *, int, va_list );

/* Bitstream manipulation */
static int  Ogg_ReadPage     ( demux_t *, ogg_page * );
static void Ogg_UpdatePCR    ( logical_stream_t *, ogg_packet * );
static void Ogg_DecodePacket ( demux_t *, logical_stream_t *, ogg_packet * );

static int Ogg_BeginningOfStream( demux_t *p_demux );
static int Ogg_FindLogicalStreams( demux_t *p_demux );
static void Ogg_EndOfStream( demux_t *p_demux );

/* Logical bitstream headers */
static void Ogg_ReadTheoraHeader( logical_stream_t *, ogg_packet * );
static void Ogg_ReadVorbisHeader( logical_stream_t *, ogg_packet * );
static void Ogg_ReadSpeexHeader( logical_stream_t *, ogg_packet * );
static void Ogg_ReadFlacHeader( demux_t *, logical_stream_t *, ogg_packet * );
static void Ogg_ReadAnnodexHeader( vlc_object_t *, logical_stream_t *, ogg_packet * );

/*****************************************************************************
 * Open: initializes ogg demux structures
 *****************************************************************************/
static int Open( vlc_object_t * p_this )
{
    demux_t *p_demux = (demux_t *)p_this;
    demux_sys_t    *p_sys;
    uint8_t        *p_peek;


    /* Check if we are dealing with an ogg stream */
    if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 ) return VLC_EGENERIC;
    if( strcmp( p_demux->psz_demux, "ogg" ) && strncmp( p_peek, "OggS", 4 ) )
    {
        return VLC_EGENERIC;
    }

    /* Set exported functions */
    p_demux->pf_demux = Demux;
    p_demux->pf_control = Control;
    p_demux->p_sys = p_sys = malloc( sizeof( demux_sys_t ) );

    memset( p_sys, 0, sizeof( demux_sys_t ) );
    p_sys->i_bitrate = 0;
    p_sys->pp_stream = NULL;

    /* Begnning of stream, tell the demux to look for elementary streams. */
    p_sys->i_eos = 0;

    /* Initialize the Ogg physical bitstream parser */
    ogg_sync_init( &p_sys->oy );

    return VLC_SUCCESS;
}

/*****************************************************************************
 * Close: frees unused data
 *****************************************************************************/
static void Close( vlc_object_t *p_this )
{
    demux_t *p_demux = (demux_t *)p_this;
    demux_sys_t *p_sys = p_demux->p_sys  ;

    /* Cleanup the bitstream parser */
    ogg_sync_clear( &p_sys->oy );

    Ogg_EndOfStream( p_demux );

    free( p_sys );
}

/*****************************************************************************
 * Demux: reads and demuxes data packets
 *****************************************************************************
 * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
 *****************************************************************************/
static int Demux( demux_t * p_demux )
{
    demux_sys_t *p_sys = p_demux->p_sys;
    ogg_page    oggpage;
    ogg_packet  oggpacket;
    int         i_stream;


    if( p_sys->i_eos == p_sys->i_streams )
    {
        if( p_sys->i_eos )
        {
            msg_Dbg( p_demux, "end of a group of logical streams" );
            Ogg_EndOfStream( p_demux );
        }

        p_sys->i_eos = 0;
        if( Ogg_BeginningOfStream( p_demux ) != VLC_SUCCESS ) return 0;

        msg_Dbg( p_demux, "beginning of a group of logical streams" );
        es_out_Control( p_demux->out, ES_OUT_RESET_PCR );
    }

    /*
     * Demux an ogg page from the stream
     */
    if( Ogg_ReadPage( p_demux, &oggpage ) != VLC_SUCCESS )
    {
        return 0; /* EOF */
    }

    /* Test for End of Stream */
    if( ogg_page_eos( &oggpage ) ) p_sys->i_eos++;


    for( i_stream = 0; i_stream < p_sys->i_streams; i_stream++ )
    {
        logical_stream_t *p_stream = p_sys->pp_stream[i_stream];

        if( ogg_stream_pagein( &p_stream->os, &oggpage ) != 0 )
            continue;

        while( ogg_stream_packetout( &p_stream->os, &oggpacket ) > 0 )
        {
            /* Read info from any secondary header packets, if there are any */
            if( p_stream->secondary_header_packets > 0 )
            {
                if( p_stream->fmt.i_codec == VLC_FOURCC('t','h','e','o') &&
                        oggpacket.bytes >= 7 &&
                        ! strncmp( &oggpacket.packet[1], "theora", 6 ) )
                {
                    Ogg_ReadTheoraHeader( p_stream, &oggpacket );
                    p_stream->secondary_header_packets = 0;
                }
                else if( p_stream->fmt.i_codec == VLC_FOURCC('v','o','r','b') &&
                        oggpacket.bytes >= 7 &&
                        ! strncmp( &oggpacket.packet[1], "vorbis", 6 ) )
                {
                    Ogg_ReadVorbisHeader( p_stream, &oggpacket );
                    p_stream->secondary_header_packets = 0;
                }
                else if ( p_stream->fmt.i_codec == VLC_FOURCC('c','m','m','l') )
                {
                    p_stream->secondary_header_packets = 0;
                }
            }

            if( p_stream->b_reinit )
            {
                /* If synchro is re-initialized we need to drop all the packets
                 * until we find a new dated one. */
                Ogg_UpdatePCR( p_stream, &oggpacket );

                if( p_stream->i_pcr >= 0 )
                {
                    p_stream->b_reinit = 0;
                }
                else
                {
                    p_stream->i_interpolated_pcr = -1;
                    continue;
                }

                /* An Ogg/vorbis packet contains an end date granulepos */
                if( p_stream->fmt.i_codec == VLC_FOURCC( 'v','o','r','b' ) ||
                    p_stream->fmt.i_codec == VLC_FOURCC( 's','p','x',' ' ) ||
                    p_stream->fmt.i_codec == VLC_FOURCC( 'f','l','a','c' ) )
                {
                    if( ogg_stream_packetout( &p_stream->os, &oggpacket ) > 0 )
                    {
                        Ogg_DecodePacket( p_demux, p_stream, &oggpacket );
                    }
                    else
                    {
                        es_out_Control( p_demux->out, ES_OUT_SET_PCR,
                                        p_stream->i_pcr );
                    }
                    continue;
                }
            }

            Ogg_DecodePacket( p_demux, p_stream, &oggpacket );
        }
        break;
    }

    i_stream = 0; p_sys->i_pcr = -1;
    for( ; i_stream < p_sys->i_streams; i_stream++ )
    {
        logical_stream_t *p_stream = p_sys->pp_stream[i_stream];

        if( p_stream->fmt.i_cat == SPU_ES )
            continue;
        if( p_stream->i_interpolated_pcr < 0 )
            continue;

        if( p_sys->i_pcr < 0 || p_stream->i_interpolated_pcr < p_sys->i_pcr )
            p_sys->i_pcr = p_stream->i_interpolated_pcr;
    }

    if( p_sys->i_pcr >= 0 )
    {
        es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_pcr );
    }