Libav
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00001 /* 00002 * 4X Technologies .4xm File Demuxer (no muxer) 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 00030 #include "libavutil/intreadwrite.h" 00031 #include "avformat.h" 00032 00033 #define RIFF_TAG MKTAG('R', 'I', 'F', 'F') 00034 #define FOURXMV_TAG MKTAG('4', 'X', 'M', 'V') 00035 #define LIST_TAG MKTAG('L', 'I', 'S', 'T') 00036 #define HEAD_TAG MKTAG('H', 'E', 'A', 'D') 00037 #define TRK__TAG MKTAG('T', 'R', 'K', '_') 00038 #define MOVI_TAG MKTAG('M', 'O', 'V', 'I') 00039 #define VTRK_TAG MKTAG('V', 'T', 'R', 'K') 00040 #define STRK_TAG MKTAG('S', 'T', 'R', 'K') 00041 #define std__TAG MKTAG('s', 't', 'd', '_') 00042 #define name_TAG MKTAG('n', 'a', 'm', 'e') 00043 #define vtrk_TAG MKTAG('v', 't', 'r', 'k') 00044 #define strk_TAG MKTAG('s', 't', 'r', 'k') 00045 #define ifrm_TAG MKTAG('i', 'f', 'r', 'm') 00046 #define pfrm_TAG MKTAG('p', 'f', 'r', 'm') 00047 #define cfrm_TAG MKTAG('c', 'f', 'r', 'm') 00048 #define ifr2_TAG MKTAG('i', 'f', 'r', '2') 00049 #define pfr2_TAG MKTAG('p', 'f', 'r', '2') 00050 #define cfr2_TAG MKTAG('c', 'f', 'r', '2') 00051 #define snd__TAG MKTAG('s', 'n', 'd', '_') 00052 00053 #define vtrk_SIZE 0x44 00054 #define strk_SIZE 0x28 00055 00056 #define GET_LIST_HEADER() \ 00057 fourcc_tag = get_le32(pb); \ 00058 size = get_le32(pb); \ 00059 if (fourcc_tag != LIST_TAG) \ 00060 return AVERROR_INVALIDDATA; \ 00061 fourcc_tag = get_le32(pb); 00062 00063 typedef struct AudioTrack { 00064 int sample_rate; 00065 int bits; 00066 int channels; 00067 int stream_index; 00068 int adpcm; 00069 int64_t audio_pts; 00070 } AudioTrack; 00071 00072 typedef struct FourxmDemuxContext { 00073 int width; 00074 int height; 00075 int video_stream_index; 00076 int track_count; 00077 AudioTrack *tracks; 00078 00079 int64_t video_pts; 00080 float fps; 00081 } FourxmDemuxContext; 00082 00083 static int fourxm_probe(AVProbeData *p) 00084 { 00085 if ((AV_RL32(&p->buf[0]) != RIFF_TAG) || 00086 (AV_RL32(&p->buf[8]) != FOURXMV_TAG)) 00087 return 0; 00088 00089 return AVPROBE_SCORE_MAX; 00090 } 00091 00092 static int fourxm_read_header(AVFormatContext *s, 00093 AVFormatParameters *ap) 00094 { 00095 ByteIOContext *pb = s->pb; 00096 unsigned int fourcc_tag; 00097 unsigned int size; 00098 int header_size; 00099 FourxmDemuxContext *fourxm = s->priv_data; 00100 unsigned char *header; 00101 int i, ret; 00102 AVStream *st; 00103 00104 fourxm->track_count = 0; 00105 fourxm->tracks = NULL; 00106 fourxm->fps = 1.0; 00107 00108 /* skip the first 3 32-bit numbers */ 00109 url_fseek(pb, 12, SEEK_CUR); 00110 00111 /* check for LIST-HEAD */ 00112 GET_LIST_HEADER(); 00113 header_size = size - 4; 00114 if (fourcc_tag != HEAD_TAG || header_size < 0) 00115 return AVERROR_INVALIDDATA; 00116 00117 /* allocate space for the header and load the whole thing */ 00118 header = av_malloc(header_size); 00119 if (!header) 00120 return AVERROR(ENOMEM); 00121 if (get_buffer(pb, header, header_size) != header_size){ 00122 av_free(header); 00123 return AVERROR(EIO); 00124 } 00125 00126 /* take the lazy approach and search for any and all vtrk and strk chunks */ 00127 for (i = 0; i < header_size - 8; i++) { 00128 fourcc_tag = AV_RL32(&header[i]); 00129 size = AV_RL32(&header[i + 4]); 00130 00131 if (fourcc_tag == std__TAG) { 00132 fourxm->fps = av_int2flt(AV_RL32(&header[i + 12])); 00133 } else if (fourcc_tag == vtrk_TAG) { 00134 /* check that there is enough data */ 00135 if (size != vtrk_SIZE) { 00136 ret= AVERROR_INVALIDDATA; 00137 goto fail; 00138 } 00139 fourxm->width = AV_RL32(&header[i + 36]); 00140 fourxm->height = AV_RL32(&header[i + 40]); 00141 00142 /* allocate a new AVStream */ 00143 st = av_new_stream(s, 0); 00144 if (!st){ 00145 ret= AVERROR(ENOMEM); 00146 goto fail; 00147 } 00148 av_set_pts_info(st, 60, 1, fourxm->fps); 00149 00150 fourxm->video_stream_index = st->index; 00151 00152 st->codec->codec_type = AVMEDIA_TYPE_VIDEO; 00153 st->codec->codec_id = CODEC_ID_4XM; 00154 st->codec->extradata_size = 4; 00155 st->codec->extradata = av_malloc(4); 00156 AV_WL32(st->codec->extradata, AV_RL32(&header[i + 16])); 00157 st->codec->width = fourxm->width; 00158 st->codec->height = fourxm->height; 00159 00160 i += 8 + size; 00161 } else if (fourcc_tag == strk_TAG) { 00162 int current_track; 00163 /* check that there is enough data */ 00164 if (size != strk_SIZE) { 00165 ret= AVERROR_INVALIDDATA; 00166 goto fail; 00167 } 00168 current_track = AV_RL32(&header[i + 8]); 00169 if((unsigned)current_track >= UINT_MAX / sizeof(AudioTrack) - 1){ 00170 av_log(s, AV_LOG_ERROR, "current_track too large\n"); 00171 ret= -1; 00172 goto fail; 00173 } 00174 if (current_track + 1 > fourxm->track_count) { 00175 fourxm->track_count = current_track + 1; 00176 fourxm->tracks = av_realloc(fourxm->tracks, 00177 fourxm->track_count * sizeof(AudioTrack)); 00178 if (!fourxm->tracks) { 00179 ret= AVERROR(ENOMEM); 00180 goto fail; 00181 } 00182 } 00183 fourxm->tracks[current_track].adpcm = AV_RL32(&header[i + 12]); 00184 fourxm->tracks[current_track].channels = AV_RL32(&header[i + 36]); 00185 fourxm->tracks[current_track].sample_rate = AV_RL32(&header[i + 40]); 00186 fourxm->tracks[current_track].bits = AV_RL32(&header[i + 44]); 00187 fourxm->tracks[current_track].audio_pts = 0; 00188 i += 8 + size; 00189 00190 /* allocate a new AVStream */ 00191 st = av_new_stream(s, current_track); 00192 if (!st){ 00193 ret= AVERROR(ENOMEM); 00194 goto fail; 00195 } 00196 00197 av_set_pts_info(st, 60, 1, fourxm->tracks[current_track].sample_rate); 00198 00199 fourxm->tracks[current_track].stream_index = st->index; 00200 00201 st->codec->codec_type = AVMEDIA_TYPE_AUDIO; 00202 st->codec->codec_tag = 0; 00203 st->codec->channels = fourxm->tracks[current_track].channels; 00204 st->codec->sample_rate = fourxm->tracks[current_track].sample_rate; 00205 st->codec->bits_per_coded_sample = fourxm->tracks[current_track].bits; 00206 st->codec->bit_rate = st->codec->channels * st->codec->sample_rate * 00207 st->codec->bits_per_coded_sample; 00208 st->codec->block_align = st->codec->channels * st->codec->bits_per_coded_sample; 00209 if (fourxm->tracks[current_track].adpcm){ 00210 st->codec->codec_id = CODEC_ID_ADPCM_4XM; 00211 }else if (st->codec->bits_per_coded_sample == 8){ 00212 st->codec->codec_id = CODEC_ID_PCM_U8; 00213 }else 00214 st->codec->codec_id = CODEC_ID_PCM_S16LE; 00215 } 00216 } 00217 00218 /* skip over the LIST-MOVI chunk (which is where the stream should be */ 00219 GET_LIST_HEADER(); 00220 if (fourcc_tag != MOVI_TAG){ 00221 ret= AVERROR_INVALIDDATA; 00222 goto fail; 00223 } 00224 00225 av_free(header); 00226 /* initialize context members */ 00227 fourxm->video_pts = -1; /* first frame will push to 0 */ 00228 00229 return 0; 00230 fail: 00231 av_freep(&fourxm->tracks); 00232 av_free(header); 00233 return ret; 00234 } 00235 00236 static int fourxm_read_packet(AVFormatContext *s, 00237 AVPacket *pkt) 00238 { 00239 FourxmDemuxContext *fourxm = s->priv_data; 00240 ByteIOContext *pb = s->pb; 00241 unsigned int fourcc_tag; 00242 unsigned int size, out_size; 00243 int ret = 0; 00244 unsigned int track_number; 00245 int packet_read = 0; 00246 unsigned char header[8]; 00247 int audio_frame_count; 00248 00249 while (!packet_read) { 00250 00251 if ((ret = get_buffer(s->pb, header, 8)) < 0) 00252 return ret; 00253 fourcc_tag = AV_RL32(&header[0]); 00254 size = AV_RL32(&header[4]); 00255 if (url_feof(pb)) 00256 return AVERROR(EIO); 00257 switch (fourcc_tag) { 00258 00259 case LIST_TAG: 00260 /* this is a good time to bump the video pts */ 00261 fourxm->video_pts ++; 00262 00263 /* skip the LIST-* tag and move on to the next fourcc */ 00264 get_le32(pb); 00265 break; 00266 00267 case ifrm_TAG: 00268 case pfrm_TAG: 00269 case cfrm_TAG: 00270 case ifr2_TAG: 00271 case pfr2_TAG: 00272 case cfr2_TAG: 00273 /* allocate 8 more bytes than 'size' to account for fourcc 00274 * and size */ 00275 if (size + 8 < size || av_new_packet(pkt, size + 8)) 00276 return AVERROR(EIO); 00277 pkt->stream_index = fourxm->video_stream_index; 00278 pkt->pts = fourxm->video_pts; 00279 pkt->pos = url_ftell(s->pb); 00280 memcpy(pkt->data, header, 8); 00281 ret = get_buffer(s->pb, &pkt->data[8], size); 00282 00283 if (ret < 0){ 00284 av_free_packet(pkt); 00285 }else 00286 packet_read = 1; 00287 break; 00288 00289 case snd__TAG: 00290 track_number = get_le32(pb); 00291 out_size= get_le32(pb); 00292 size-=8; 00293 00294 if (track_number < fourxm->track_count) { 00295 ret= av_get_packet(s->pb, pkt, size); 00296 if(ret<0) 00297 return AVERROR(EIO); 00298 pkt->stream_index = 00299 fourxm->tracks[track_number].stream_index; 00300 pkt->pts = fourxm->tracks[track_number].audio_pts; 00301 packet_read = 1; 00302 00303 /* pts accounting */ 00304 audio_frame_count = size; 00305 if (fourxm->tracks[track_number].adpcm) 00306 audio_frame_count -= 00307 2 * (fourxm->tracks[track_number].channels); 00308 audio_frame_count /= 00309 fourxm->tracks[track_number].channels; 00310 if (fourxm->tracks[track_number].adpcm){ 00311 audio_frame_count *= 2; 00312 }else 00313 audio_frame_count /= 00314 (fourxm->tracks[track_number].bits / 8); 00315 fourxm->tracks[track_number].audio_pts += audio_frame_count; 00316 00317 } else { 00318 url_fseek(pb, size, SEEK_CUR); 00319 } 00320 break; 00321 00322 default: 00323 url_fseek(pb, size, SEEK_CUR); 00324 break; 00325 } 00326 } 00327 return ret; 00328 } 00329 00330 static int fourxm_read_close(AVFormatContext *s) 00331 { 00332 FourxmDemuxContext *fourxm = s->priv_data; 00333 00334 av_freep(&fourxm->tracks); 00335 00336 return 0; 00337 } 00338 00339 AVInputFormat fourxm_demuxer = { 00340 "4xm", 00341 NULL_IF_CONFIG_SMALL("4X Technologies format"), 00342 sizeof(FourxmDemuxContext), 00343 fourxm_probe, 00344 fourxm_read_header, 00345 fourxm_read_packet, 00346 fourxm_read_close, 00347 };