diff options
Diffstat (limited to 'media/libtremor/lib/tremor_synthesis.c')
| -rw-r--r-- | media/libtremor/lib/tremor_synthesis.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/media/libtremor/lib/tremor_synthesis.c b/media/libtremor/lib/tremor_synthesis.c new file mode 100644 index 0000000000..c7680f6d02 --- /dev/null +++ b/media/libtremor/lib/tremor_synthesis.c @@ -0,0 +1,131 @@ +/******************************************************************** + * * + * THIS FILE IS PART OF THE OggVorbis 'TREMOR' CODEC SOURCE CODE. * + * * + * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS * + * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE * + * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. * + * * + * THE OggVorbis 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2003 * + * BY THE Xiph.Org FOUNDATION http://www.xiph.org/ * + * * + ******************************************************************** + + function: single-block PCM synthesis + last mod: $Id: synthesis.c,v 1.4 2003/03/29 03:07:21 xiphmont Exp $ + + ********************************************************************/ + +#include <stdio.h> +#include <ogg/ogg.h> +#include "ivorbiscodec.h" +#include "codec_internal.h" +#include "registry.h" +#include "misc.h" +#include "block.h" + +static int _vorbis_synthesis1(vorbis_block *vb,ogg_packet *op,int decodep){ + vorbis_dsp_state *vd= vb ? vb->vd : 0; + private_state *b= vd ? (private_state *)vd->backend_state: 0; + vorbis_info *vi= vd ? vd->vi : 0; + codec_setup_info *ci= vi ? (codec_setup_info *)vi->codec_setup : 0; + oggpack_buffer *opb=vb ? &vb->opb : 0; + int type,mode,i; + + if (!vd || !b || !vi || !ci || !opb) { + return OV_EBADPACKET; + } + + /* first things first. Make sure decode is ready */ + _vorbis_block_ripcord(vb); + oggpack_readinit(opb,op->packet,op->bytes); + + /* Check the packet type */ + if(oggpack_read(opb,1)!=0){ + /* Oops. This is not an audio data packet */ + return(OV_ENOTAUDIO); + } + + /* read our mode and pre/post windowsize */ + mode=oggpack_read(opb,b->modebits); + if(mode==-1)return(OV_EBADPACKET); + + vb->mode=mode; + if(!ci->mode_param[mode]){ + return(OV_EBADPACKET); + } + + vb->W=ci->mode_param[mode]->blockflag; + if(vb->W){ + vb->lW=oggpack_read(opb,1); + vb->nW=oggpack_read(opb,1); + if(vb->nW==-1) return(OV_EBADPACKET); + }else{ + vb->lW=0; + vb->nW=0; + } + + /* more setup */ + vb->granulepos=op->granulepos; + vb->sequence=op->packetno-3; /* first block is third packet */ + vb->eofflag=op->e_o_s; + + if(decodep){ + /* alloc pcm passback storage */ + vb->pcmend=ci->blocksizes[vb->W]; + vb->pcm=(ogg_int32_t **)_vorbis_block_alloc(vb,sizeof(*vb->pcm)*vi->channels); + for(i=0;i<vi->channels;i++) + vb->pcm[i]=(ogg_int32_t *)_vorbis_block_alloc(vb,vb->pcmend*sizeof(*vb->pcm[i])); + + /* unpack_header enforces range checking */ + type=ci->map_type[ci->mode_param[mode]->mapping]; + + return(_mapping_P[type]->inverse(vb,b->mode[mode])); + }else{ + /* no pcm */ + vb->pcmend=0; + vb->pcm=NULL; + + return(0); + } +} + +int vorbis_synthesis(vorbis_block *vb,ogg_packet *op){ + return _vorbis_synthesis1(vb,op,1); +} + +/* used to track pcm position without actually performing decode. + Useful for sequential 'fast forward' */ +int vorbis_synthesis_trackonly(vorbis_block *vb,ogg_packet *op){ + return _vorbis_synthesis1(vb,op,0); +} + +long vorbis_packet_blocksize(vorbis_info *vi,ogg_packet *op){ + codec_setup_info *ci=(codec_setup_info *)vi->codec_setup; + oggpack_buffer opb; + int mode; + + oggpack_readinit(&opb,op->packet,op->bytes); + + /* Check the packet type */ + if(oggpack_read(&opb,1)!=0){ + /* Oops. This is not an audio data packet */ + return(OV_ENOTAUDIO); + } + + { + int modebits=0; + int v=ci->modes; + while(v>1){ + modebits++; + v>>=1; + } + + /* read our mode and pre/post windowsize */ + mode=oggpack_read(&opb,modebits); + } + if(mode==-1 || !ci->mode_param[mode])return(OV_EBADPACKET); + return(ci->blocksizes[ci->mode_param[mode]->blockflag]); +} + + |