theora.c

video linux conference

/*****************************************************************************
 * theora.c: theora decoder module making use of libtheora.
 *****************************************************************************
 * Copyright (C) 1999-2001 VideoLAN
 * $Id: theora.c 11030 2005-05-16 13:32:12Z gbazin $
 *
 * Authors: Gildas Bazin <[e-mail]>
 *
 * 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/decoder.h>
#include <vlc/input.h>
#include <vlc/sout.h>

#include <ogg/ogg.h>

#include <theora/theora.h>

/*****************************************************************************
 * decoder_sys_t : theora decoder descriptor
 *****************************************************************************/
struct decoder_sys_t
{
    /* Module mode */
    vlc_bool_t b_packetizer;

    /*
     * Input properties
     */
    int i_headers;

    /*
     * Theora properties
     */
    theora_info      ti;                        /* theora bitstream settings */
    theora_comment   tc;                            /* theora comment header */
    theora_state     td;                   /* theora bitstream user comments */

    /*
     * Decoding properties
     */
    vlc_bool_t b_decoded_first_keyframe;

    /*
     * Common properties
     */
    mtime_t i_pts;
};

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
static int  OpenDecoder   ( vlc_object_t * );
static int  OpenPacketizer( vlc_object_t * );
static void CloseDecoder  ( vlc_object_t * );

static void *DecodeBlock  ( decoder_t *, block_t ** );
static int  ProcessHeaders( decoder_t * );
static void *ProcessPacket ( decoder_t *, ogg_packet *, block_t ** );

static picture_t *DecodePacket( decoder_t *, ogg_packet * );

static void ParseTheoraComments( decoder_t * );
static void theora_CopyPicture( decoder_t *, picture_t *, yuv_buffer * );

static int  OpenEncoder( vlc_object_t *p_this );
static void CloseEncoder( vlc_object_t *p_this );
static block_t *Encode( encoder_t *p_enc, picture_t *p_pict );

/*****************************************************************************
 * Module descriptor
 *****************************************************************************/
#define ENC_QUALITY_TEXT N_("Encoding quality")
#define ENC_QUALITY_LONGTEXT N_( \
  "Allows you to specify a quality between 1 (low) and 10 (high), instead " \
  "of specifying a particular bitrate. This will produce a VBR stream." )

vlc_module_begin();
    set_category( CAT_INPUT );
    set_subcategory( SUBCAT_INPUT_VCODEC );
    set_shortname( "Theora" );
    set_description( _("Theora video decoder") );
    set_capability( "decoder", 100 );
    set_callbacks( OpenDecoder, CloseDecoder );
    add_shortcut( "theora" );

    add_submodule();
    set_description( _("Theora video packetizer") );
    set_capability( "packetizer", 100 );
    set_callbacks( OpenPacketizer, CloseDecoder );
    add_shortcut( "theora" );

    add_submodule();
    set_description( _("Theora video encoder") );
    set_capability( "encoder", 150 );
    set_callbacks( OpenEncoder, CloseEncoder );
    add_shortcut( "theora" );

#   define ENC_CFG_PREFIX "sout-theora-"
    add_integer( ENC_CFG_PREFIX "quality", 2, NULL, ENC_QUALITY_TEXT,
                 ENC_QUALITY_LONGTEXT, VLC_FALSE );
vlc_module_end();

static const char *ppsz_enc_options[] = {
    "quality", NULL
};

/*****************************************************************************
 * OpenDecoder: probe the decoder and return score
 *****************************************************************************/
static int OpenDecoder( vlc_object_t *p_this )
{
    decoder_t *p_dec = (decoder_t*)p_this;
    decoder_sys_t *p_sys;

    if( p_dec->fmt_in.i_codec != VLC_FOURCC('t','h','e','o') )
    {
        return VLC_EGENERIC;
    }

    /* Allocate the memory needed to store the decoder's structure */
    if( ( p_dec->p_sys = p_sys =
          (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
    {
        msg_Err( p_dec, "out of memory" );
        return VLC_EGENERIC;
    }
    p_dec->p_sys->b_packetizer = VLC_FALSE;

    p_sys->i_pts = 0;
    p_sys->b_decoded_first_keyframe = VLC_FALSE;

    /* Set output properties */
    p_dec->fmt_out.i_cat = VIDEO_ES;
    p_dec->fmt_out.i_codec = VLC_FOURCC('I','4','2','0');

    /* Set callbacks */
    p_dec->pf_decode_video = (picture_t *(*)(decoder_t *, block_t **))
        DecodeBlock;
    p_dec->pf_packetize    = (block_t *(*)(decoder_t *, block_t **))
        DecodeBlock;

    /* Init supporting Theora structures needed in header parsing */
    theora_comment_init( &p_sys->tc );
    theora_info_init( &p_sys->ti );

    p_sys->i_headers = 0;

    return VLC_SUCCESS;
}

static int OpenPacketizer( vlc_object_t *p_this )
{
    decoder_t *p_dec = (decoder_t*)p_this;

    int i_ret = OpenDecoder( p_this );

    if( i_ret == VLC_SUCCESS )
    {
        p_dec->p_sys->b_packetizer = VLC_TRUE;
        p_dec->fmt_out.i_codec = VLC_FOURCC( 't', 'h', 'e', 'o' );
    }

    return i_ret;
}

/****************************************************************************
 * DecodeBlock: the whole thing
 ****************************************************************************
 * This function must be fed with ogg packets.
 ****************************************************************************/
static void *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    block_t *p_block;
    ogg_packet oggpacket;

    if( !pp_block || !*pp_block ) return NULL;

    p_block = *pp_block;

    /* Block to Ogg packet */
    oggpacket.packet = p_block->p_buffer;
    oggpacket.bytes = p_block->i_buffer;
    oggpacket.granulepos = p_block->i_dts;
    oggpacket.b_o_s = 0;
    oggpacket.e_o_s = 0;
    oggpacket.packetno = 0;

    /* Check for headers */
    if( p_sys->i_headers == 0 && p_dec->fmt_in.i_extra )
    {
        /* Headers already available as extra data */
        p_sys->i_headers = 3;
    }
    else if( oggpacket.bytes && p_sys->i_headers < 3 )
    {
        /* Backup headers as extra data */
        uint8_t *p_extra;

        p_dec->fmt_in.p_extra =
            realloc( p_dec->fmt_in.p_extra, p_dec->fmt_in.i_extra +
                     oggpacket.bytes + 2 );
        p_extra = p_dec->fmt_in.p_extra + p_dec->fmt_in.i_extra;
        *(p_extra++) = oggpacket.bytes >> 8;
        *(p_extra++) = oggpacket.bytes & 0xFF;

        memcpy( p_extra, oggpacket.packet, oggpacket.bytes );
        p_dec->fmt_in.i_extra += oggpacket.bytes + 2;

        block_Release( *pp_block );
        p_sys->i_headers++;
        return NULL;
    }

    if( p_sys->i_headers == 3 )
    {
        if( ProcessHeaders( p_dec ) != VLC_SUCCESS )
        {
            p_sys->i_headers = 0;
            p_dec->fmt_in.i_extra = 0;
            block_Release( *pp_block );
            return NULL;
        }
        else p_sys->i_headers++;
    }

    return ProcessPacket( p_dec, &oggpacket, pp_block );
}

/*****************************************************************************
 * ProcessHeaders: process Theora headers.
 *****************************************************************************/
static int ProcessHeaders( decoder_t *p_dec )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    ogg_packet oggpacket;
    uint8_t *p_extra;
    int i_extra;

    if( !p_dec->fmt_in.i_extra ) return VLC_EGENERIC;

    oggpacket.granulepos = -1;
    oggpacket.b_o_s = 1; /* yes this actually is a b_o_s packet :) */
    oggpacket.e_o_s = 0;
    oggpacket.packetno = 0;
    p_extra = p_dec->fmt_in.p_extra;
    i_extra = p_dec->fmt_in.i_extra;

    /* Take care of the initial Vorbis header */
    oggpacket.bytes = *(p_extra++) << 8;
    oggpacket.bytes |= (*(p_extra++) & 0xFF);
    oggpacket.packet = p_extra;
    p_extra += oggpacket.bytes;
    i_extra -= (oggpacket.bytes + 2);
    if( i_extra < 0 )
    {
        msg_Err( p_dec, "header data corrupted");
        return VLC_EGENERIC;
    }

    if( theora_decode_header( &p_sys->ti, &p_sys->tc, &oggpacket ) < 0 )
    {
        msg_Err( p_dec, "This bitstream does not contain Theora video data" );
        return VLC_EGENERIC;
    }

    /* Set output properties */
    p_dec->fmt_out.video.i_width = p_sys->ti.width;
    p_dec->fmt_out.video.i_height = p_sys->ti.height;
    if( p_sys->ti.frame_width && p_sys->ti.frame_height )
    {
        p_dec->fmt_out.video.i_width = p_sys->ti.frame_width;
        p_dec->fmt_out.video.i_height = p_sys->ti.frame_height;
    }

    if( p_sys->ti.aspect_denominator && p_sys->ti.aspect_numerator )
    {
        p_dec->fmt_out.video.i_aspect = ((int64_t)VOUT_ASPECT_FACTOR) *
            ( p_sys->ti.aspect_numerator * p_sys->ti.width ) /
            ( p_sys->ti.aspect_denominator * p_sys->ti.height );
    }
    else
    {
        p_dec->fmt_out.video.i_aspect = VOUT_ASPECT_FACTOR *
            p_sys->ti.frame_width / p_sys->ti.frame_height;
    }

    if( p_sys->ti.fps_numerator > 0 && p_sys->ti.fps_denominator > 0 )
    {
        p_dec->fmt_out.video.i_frame_rate = p_sys->ti.fps_numerator;
        p_dec->fmt_out.video.i_frame_rate_base = p_sys->ti.fps_denominator;
    }

    msg_Dbg( p_dec, "%dx%d %.02f fps video, frame content "
             "is %dx%d with offset (%d,%d)",
             p_sys->ti.width, p_sys->ti.height,
             (double)p_sys->ti.fps_numerator/p_sys->ti.fps_denominator,
             p_sys->ti.frame_width, p_sys->ti.frame_height,
             p_sys->ti.offset_x, p_sys->ti.offset_y );

    /* Sanity check that seems necessary for some corrupted files */
    if( p_sys->ti.width < p_sys->ti.frame_width ||
        p_sys->ti.height < p_sys->ti.frame_height )
    {
        msg_Warn( p_dec, "trying to correct invalid theora header "
                  "(frame size (%dx%d) is smaller than frame content (%d,%d))",
                  p_sys->ti.width, p_sys->ti.height,
                  p_sys->ti.frame_width, p_sys->ti.frame_height );

        if( p_sys->ti.width < p_sys->ti.frame_width )
            p_sys->ti.width = p_sys->ti.frame_width;
        if( p_sys->ti.height < p_sys->ti.frame_height )
            p_sys->ti.height = p_sys->ti.frame_height;
    }

    /* The next packet in order is the comments header */
    oggpacket.b_o_s = 0;
    oggpacket.bytes = *(p_extra++) << 8;
    oggpacket.bytes |= (*(p_extra++) & 0xFF);
    oggpacket.packet = p_extra;
    p_extra += oggpacket.bytes;
    i_extra -= (oggpacket.bytes + 2);
    if( i_extra < 0 )
    {
        msg_Err( p_dec, "header data corrupted");
        return VLC_EGENERIC;
    }

    /* The next packet in order is the comments header */
    if( theora_decode_header( &p_sys->ti, &p_sys->tc, &oggpacket ) < 0 )
    {
        msg_Err( p_dec, "2nd Theora header is corrupted" );
        return VLC_EGENERIC;
    }

    ParseTheoraComments( p_dec );

    /* The next packet in order is the codebooks header
     * We need to watch out that this packet is not missing as a
     * missing or corrupted header is fatal. */
    oggpacket.bytes = *(p_extra++) << 8;
    oggpacket.bytes |= (*(p_extra++) & 0xFF);
    oggpacket.packet = p_extra;
    i_extra -= (oggpacket.bytes + 2);
    if( i_extra < 0 )
    {
        msg_Err( p_dec, "header data corrupted");
        return VLC_EGENERIC;
    }

    /* The next packet in order is the codebooks header
     * We need to watch out that this packet is not missing as a
     * missing or corrupted header is fatal */
    if( theora_decode_header( &p_sys->ti, &p_sys->tc, &oggpacket ) < 0 )
    {
        msg_Err( p_dec, "3rd Theora header is corrupted" );
        return VLC_EGENERIC;
    }

    if( !p_sys->b_packetizer )
    {
        /* We have all the headers, initialize decoder */
        theora_decode_init( &p_sys->td, &p_sys->ti );
    }
    else
    {
        p_dec->fmt_out.i_extra = p_dec->fmt_in.i_extra;
        p_dec->fmt_out.p_extra =
            realloc( p_dec->fmt_out.p_extra, p_dec->fmt_out.i_extra );
        memcpy( p_dec->fmt_out.p_extra,
                p_dec->fmt_in.p_extra, p_dec->fmt_out.i_extra );
    }

    return VLC_SUCCESS;
}

/*****************************************************************************
 * ProcessPacket: processes a theora packet.
 *****************************************************************************/
static void *ProcessPacket( decoder_t *p_dec, ogg_packet *p_oggpacket,
                            block_t **pp_block )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    block_t *p_block = *pp_block;
    void *p_buf;

    if( ( p_block->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) ) != 0 )
    {
        /* Don't send the the first packet after a discontinuity to
         * theora_decode, otherwise we get purple/green display artifacts
         * appearing in the video output */
        return NULL;
    }

    /* Date management */
    if( p_block->i_pts > 0 && p_block->i_pts != p_sys->i_pts )
    {
        p_sys->i_pts = p_block->i_pts;
    }