FFmpeg: libavformat/westwood

00001 /*
00002  * Westwood Studios VQA Format Demuxer
00003  * Copyright (c) 2003 The ffmpeg Project
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00031 #include "libavutil/intreadwrite.h"
00032 #include "avformat.h"
00033 #include "internal.h"
00034 
00035 #define FORM_TAG MKBETAG('F', 'O', 'R', 'M')
00036 #define WVQA_TAG MKBETAG('W', 'V', 'Q', 'A')
00037 #define VQHD_TAG MKBETAG('V', 'Q', 'H', 'D')
00038 #define FINF_TAG MKBETAG('F', 'I', 'N', 'F')
00039 #define SND0_TAG MKBETAG('S', 'N', 'D', '0')
00040 #define SND1_TAG MKBETAG('S', 'N', 'D', '1')
00041 #define SND2_TAG MKBETAG('S', 'N', 'D', '2')
00042 #define VQFR_TAG MKBETAG('V', 'Q', 'F', 'R')
00043 
00044 /* don't know what these tags are for, but acknowledge their existence */
00045 #define CINF_TAG MKBETAG('C', 'I', 'N', 'F')
00046 #define CINH_TAG MKBETAG('C', 'I', 'N', 'H')
00047 #define CIND_TAG MKBETAG('C', 'I', 'N', 'D')
00048 #define PINF_TAG MKBETAG('P', 'I', 'N', 'F')
00049 #define PINH_TAG MKBETAG('P', 'I', 'N', 'H')
00050 #define PIND_TAG MKBETAG('P', 'I', 'N', 'D')
00051 #define CMDS_TAG MKBETAG('C', 'M', 'D', 'S')
00052 
00053 #define VQA_HEADER_SIZE 0x2A
00054 #define VQA_PREAMBLE_SIZE 8
00055 
00056 typedef struct WsVqaDemuxContext {
00057     int version;
00058     int bps;
00059     int channels;
00060     int sample_rate;
00061     int audio_stream_index;
00062     int video_stream_index;
00063 } WsVqaDemuxContext;
00064 
00065 static int wsvqa_probe(AVProbeData *p)
00066 {
00067     /* need 12 bytes to qualify */
00068     if (p->buf_size < 12)
00069         return 0;
00070 
00071     /* check for the VQA signatures */
00072     if ((AV_RB32(&p->buf[0]) != FORM_TAG) ||
00073         (AV_RB32(&p->buf[8]) != WVQA_TAG))
00074         return 0;
00075 
00076     return AVPROBE_SCORE_MAX;
00077 }
00078 
00079 static int wsvqa_read_header(AVFormatContext *s)
00080 {
00081     WsVqaDemuxContext *wsvqa = s->priv_data;
00082     AVIOContext *pb = s->pb;
00083     AVStream *st;
00084     unsigned char *header;
00085     unsigned char scratch[VQA_PREAMBLE_SIZE];
00086     unsigned int chunk_tag;
00087     unsigned int chunk_size;
00088     int fps;
00089 
00090     /* initialize the video decoder stream */
00091     st = avformat_new_stream(s, NULL);
00092     if (!st)
00093         return AVERROR(ENOMEM);
00094     st->start_time = 0;
00095     wsvqa->video_stream_index = st->index;
00096     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00097     st->codec->codec_id = CODEC_ID_WS_VQA;
00098     st->codec->codec_tag = 0;  /* no fourcc */
00099 
00100     /* skip to the start of the VQA header */
00101     avio_seek(pb, 20, SEEK_SET);
00102 
00103     /* the VQA header needs to go to the decoder */
00104     st->codec->extradata_size = VQA_HEADER_SIZE;
00105     st->codec->extradata = av_mallocz(VQA_HEADER_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
00106     header = (unsigned char *)st->codec->extradata;
00107     if (avio_read(pb, st->codec->extradata, VQA_HEADER_SIZE) !=
00108         VQA_HEADER_SIZE) {
00109         av_free(st->codec->extradata);
00110         return AVERROR(EIO);
00111     }
00112     st->codec->width = AV_RL16(&header[6]);
00113     st->codec->height = AV_RL16(&header[8]);
00114     fps = header[12];
00115     st->nb_frames =
00116     st->duration  = AV_RL16(&header[4]);
00117     if (fps < 1 || fps > 30) {
00118         av_log(s, AV_LOG_ERROR, "invalid fps: %d\n", fps);
00119         return AVERROR_INVALIDDATA;
00120     }
00121     avpriv_set_pts_info(st, 64, 1, fps);
00122 
00123     wsvqa->version      = AV_RL16(&header[ 0]);
00124     wsvqa->sample_rate  = AV_RL16(&header[24]);
00125     wsvqa->channels     = header[26];
00126     wsvqa->bps          = header[27];
00127     wsvqa->audio_stream_index = -1;
00128 
00129     s->ctx_flags |= AVFMTCTX_NOHEADER;
00130 
00131     /* there are 0 or more chunks before the FINF chunk; iterate until
00132      * FINF has been skipped and the file will be ready to be demuxed */
00133     do {
00134         if (avio_read(pb, scratch, VQA_PREAMBLE_SIZE) != VQA_PREAMBLE_SIZE)
00135             return AVERROR(EIO);
00136         chunk_tag = AV_RB32(&scratch[0]);
00137         chunk_size = AV_RB32(&scratch[4]);
00138 
00139         /* catch any unknown header tags, for curiousity */
00140         switch (chunk_tag) {
00141         case CINF_TAG:
00142         case CINH_TAG:
00143         case CIND_TAG:
00144         case PINF_TAG:
00145         case PINH_TAG:
00146         case PIND_TAG:
00147         case FINF_TAG:
00148         case CMDS_TAG:
00149             break;
00150 
00151         default:
00152             av_log (s, AV_LOG_ERROR, " note: unknown chunk seen (%c%c%c%c)\n",
00153                 scratch[0], scratch[1],
00154                 scratch[2], scratch[3]);
00155             break;
00156         }
00157 
00158         avio_skip(pb, chunk_size);
00159     } while (chunk_tag != FINF_TAG);
00160 
00161     return 0;
00162 }
00163 
00164 static int wsvqa_read_packet(AVFormatContext *s,
00165                              AVPacket *pkt)
00166 {
00167     WsVqaDemuxContext *wsvqa = s->priv_data;
00168     AVIOContext *pb = s->pb;
00169     int ret = -1;
00170     unsigned char preamble[VQA_PREAMBLE_SIZE];
00171     unsigned int chunk_type;
00172     unsigned int chunk_size;
00173     int skip_byte;
00174 
00175     while (avio_read(pb, preamble, VQA_PREAMBLE_SIZE) == VQA_PREAMBLE_SIZE) {
00176         chunk_type = AV_RB32(&preamble[0]);
00177         chunk_size = AV_RB32(&preamble[4]);
00178 
00179         skip_byte = chunk_size & 0x01;
00180 
00181         if ((chunk_type == SND0_TAG) || (chunk_type == SND1_TAG) ||
00182             (chunk_type == SND2_TAG) || (chunk_type == VQFR_TAG)) {
00183 
00184             ret= av_get_packet(pb, pkt, chunk_size);
00185             if (ret<0)
00186                 return AVERROR(EIO);
00187 
00188             switch (chunk_type) {
00189             case SND0_TAG:
00190             case SND1_TAG:
00191             case SND2_TAG:
00192                 if (wsvqa->audio_stream_index == -1) {
00193                     AVStream *st = avformat_new_stream(s, NULL);
00194                     if (!st)
00195                         return AVERROR(ENOMEM);
00196 
00197                     wsvqa->audio_stream_index = st->index;
00198                     if (!wsvqa->sample_rate)
00199                         wsvqa->sample_rate = 22050;
00200                     if (!wsvqa->channels)
00201                         wsvqa->channels = 1;
00202                     if (!wsvqa->bps)
00203                         wsvqa->bps = 8;
00204                     st->codec->sample_rate = wsvqa->sample_rate;
00205                     st->codec->bits_per_coded_sample = wsvqa->bps;
00206                     st->codec->channels = wsvqa->channels;
00207                     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00208 
00209                     avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
00210 
00211                     switch (chunk_type) {
00212                     case SND0_TAG:
00213                         if (wsvqa->bps == 16)
00214                             st->codec->codec_id = CODEC_ID_PCM_S16LE;
00215                         else
00216                             st->codec->codec_id = CODEC_ID_PCM_U8;
00217                         break;
00218                     case SND1_TAG:
00219                         st->codec->codec_id = CODEC_ID_WESTWOOD_SND1;
00220                         break;
00221                     case SND2_TAG:
00222                         st->codec->codec_id = CODEC_ID_ADPCM_IMA_WS;
00223                         st->codec->extradata_size = 2;
00224                         st->codec->extradata = av_mallocz(2 + FF_INPUT_BUFFER_PADDING_SIZE);
00225                         if (!st->codec->extradata)
00226                             return AVERROR(ENOMEM);
00227                         AV_WL16(st->codec->extradata, wsvqa->version);
00228                         break;
00229                     }
00230                 }
00231 
00232                 pkt->stream_index = wsvqa->audio_stream_index;
00233                 switch (chunk_type) {
00234                 case SND1_TAG:
00235                     /* unpacked size is stored in header */
00236                     pkt->duration = AV_RL16(pkt->data) / wsvqa->channels;
00237                     break;
00238                 case SND2_TAG:
00239                     /* 2 samples/byte, 1 or 2 samples per frame depending on stereo */
00240                     pkt->duration = (chunk_size * 2) / wsvqa->channels;
00241                     break;
00242                 }
00243                 break;
00244             case VQFR_TAG:
00245                 pkt->stream_index = wsvqa->video_stream_index;
00246                 pkt->duration = 1;
00247                 break;
00248             }
00249 
00250             /* stay on 16-bit alignment */
00251             if (skip_byte)
00252                 avio_skip(pb, 1);
00253 
00254             return ret;
00255         } else {
00256             switch(chunk_type){
00257             case CMDS_TAG:
00258                 break;
00259             default:
00260                 av_log(s, AV_LOG_INFO, "Skipping unknown chunk 0x%08X\n", chunk_type);
00261             }
00262             avio_skip(pb, chunk_size + skip_byte);
00263         }
00264     }
00265 
00266     return ret;
00267 }
00268 
00269 AVInputFormat ff_wsvqa_demuxer = {
00270     .name           = "wsvqa",
00271     .long_name      = NULL_IF_CONFIG_SMALL("Westwood Studios VQA format"),
00272     .priv_data_size = sizeof(WsVqaDemuxContext),
00273     .read_probe     = wsvqa_probe,
00274     .read_header    = wsvqa_read_header,
00275     .read_packet    = wsvqa_read_packet,
00276 };
libavformat/westwood_vqa.c
