FFmpeg: libavformat/avidec.c Source File

00001 /*
00002  * AVI demuxer
00003  * Copyright (c) 2001 Fabrice Bellard
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 
00022 #include "libavutil/intreadwrite.h"
00023 #include "libavutil/bswap.h"
00024 #include "avformat.h"
00025 #include "avi.h"
00026 #include "dv.h"
00027 #include "riff.h"
00028 
00029 #undef NDEBUG
00030 #include <assert.h>
00031 
00032 //#define DEBUG
00033 //#define DEBUG_SEEK
00034 
00035 typedef struct AVIStream {
00036     int64_t frame_offset; /* current frame (video) or byte (audio) counter
00037                          (used to compute the pts) */
00038     int remaining;
00039     int packet_size;
00040 
00041     int scale;
00042     int rate;
00043     int sample_size; /* size of one sample (or packet) (in the rate/scale sense) in bytes */
00044 
00045     int64_t cum_len; /* temporary storage (used during seek) */
00046 
00047     int prefix;                       
00048     int prefix_count;
00049     uint32_t pal[256];
00050     int has_pal;
00051 } AVIStream;
00052 
00053 typedef struct {
00054     int64_t  riff_end;
00055     int64_t  movi_end;
00056     int64_t  fsize;
00057     int64_t movi_list;
00058     int64_t last_pkt_pos;
00059     int index_loaded;
00060     int is_odml;
00061     int non_interleaved;
00062     int stream_index;
00063     DVDemuxContext* dv_demux;
00064 } AVIContext;
00065 
00066 static const char avi_headers[][8] = {
00067     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', ' ' },
00068     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', 'X' },
00069     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', 0x19},
00070     { 'O', 'N', '2', ' ',    'O', 'N', '2', 'f' },
00071     { 'R', 'I', 'F', 'F',    'A', 'M', 'V', ' ' },
00072     { 0 }
00073 };
00074 
00075 static int avi_load_index(AVFormatContext *s);
00076 static int guess_ni_flag(AVFormatContext *s);
00077 
00078 #ifdef DEBUG
00079 static void print_tag(const char *str, unsigned int tag, int size)
00080 {
00081     printf("%s: tag=%c%c%c%c size=0x%x\n",
00082            str, tag & 0xff,
00083            (tag >> 8) & 0xff,
00084            (tag >> 16) & 0xff,
00085            (tag >> 24) & 0xff,
00086            size);
00087 }
00088 #endif
00089 
00090 static int get_riff(AVFormatContext *s, ByteIOContext *pb)
00091 {
00092     AVIContext *avi = s->priv_data;
00093     char header[8];
00094     int i;
00095 
00096     /* check RIFF header */
00097     get_buffer(pb, header, 4);
00098     avi->riff_end = get_le32(pb);   /* RIFF chunk size */
00099     avi->riff_end += url_ftell(pb); /* RIFF chunk end */
00100     get_buffer(pb, header+4, 4);
00101 
00102     for(i=0; avi_headers[i][0]; i++)
00103         if(!memcmp(header, avi_headers[i], 8))
00104             break;
00105     if(!avi_headers[i][0])
00106         return -1;
00107 
00108     if(header[7] == 0x19)
00109         av_log(s, AV_LOG_INFO, "This file has been generated by a totally broken muxer.\n");
00110 
00111     return 0;
00112 }
00113 
00114 static int read_braindead_odml_indx(AVFormatContext *s, int frame_num){
00115     AVIContext *avi = s->priv_data;
00116     ByteIOContext *pb = s->pb;
00117     int longs_pre_entry= get_le16(pb);
00118     int index_sub_type = get_byte(pb);
00119     int index_type     = get_byte(pb);
00120     int entries_in_use = get_le32(pb);
00121     int chunk_id       = get_le32(pb);
00122     int64_t base       = get_le64(pb);
00123     int stream_id= 10*((chunk_id&0xFF) - '0') + (((chunk_id>>8)&0xFF) - '0');
00124     AVStream *st;
00125     AVIStream *ast;
00126     int i;
00127     int64_t last_pos= -1;
00128     int64_t filesize= url_fsize(s->pb);
00129 
00130 #ifdef DEBUG_SEEK
00131     av_log(s, AV_LOG_ERROR, "longs_pre_entry:%d index_type:%d entries_in_use:%d chunk_id:%X base:%16"PRIX64"\n",
00132         longs_pre_entry,index_type, entries_in_use, chunk_id, base);
00133 #endif
00134 
00135     if(stream_id > s->nb_streams || stream_id < 0)
00136         return -1;
00137     st= s->streams[stream_id];
00138     ast = st->priv_data;
00139 
00140     if(index_sub_type)
00141         return -1;
00142 
00143     get_le32(pb);
00144 
00145     if(index_type && longs_pre_entry != 2)
00146         return -1;
00147     if(index_type>1)
00148         return -1;
00149 
00150     if(filesize > 0 && base >= filesize){
00151         av_log(s, AV_LOG_ERROR, "ODML index invalid\n");
00152         if(base>>32 == (base & 0xFFFFFFFF) && (base & 0xFFFFFFFF) < filesize && filesize <= 0xFFFFFFFF)
00153             base &= 0xFFFFFFFF;
00154         else
00155             return -1;
00156     }
00157 
00158     for(i=0; i<entries_in_use; i++){
00159         if(index_type){
00160             int64_t pos= get_le32(pb) + base - 8;
00161             int len    = get_le32(pb);
00162             int key= len >= 0;
00163             len &= 0x7FFFFFFF;
00164 
00165 #ifdef DEBUG_SEEK
00166             av_log(s, AV_LOG_ERROR, "pos:%"PRId64", len:%X\n", pos, len);
00167 #endif
00168             if(url_feof(pb))
00169                 return -1;
00170 
00171             if(last_pos == pos || pos == base - 8)
00172                 avi->non_interleaved= 1;
00173             if(last_pos != pos)
00174                 av_add_index_entry(st, pos, ast->cum_len / FFMAX(1, ast->sample_size), len, 0, key ? AVINDEX_KEYFRAME : 0);
00175 
00176             if(ast->sample_size)
00177                 ast->cum_len += len;
00178             else
00179                 ast->cum_len ++;
00180             last_pos= pos;
00181         }else{
00182             int64_t offset, pos;
00183             int duration;
00184             offset = get_le64(pb);
00185             get_le32(pb);       /* size */
00186             duration = get_le32(pb);
00187 
00188             if(url_feof(pb))
00189                 return -1;
00190 
00191             pos = url_ftell(pb);
00192 
00193             url_fseek(pb, offset+8, SEEK_SET);
00194             read_braindead_odml_indx(s, frame_num);
00195             frame_num += duration;
00196 
00197             url_fseek(pb, pos, SEEK_SET);
00198         }
00199     }
00200     avi->index_loaded=1;
00201     return 0;
00202 }
00203 
00204 static void clean_index(AVFormatContext *s){
00205     int i;
00206     int64_t j;
00207 
00208     for(i=0; i<s->nb_streams; i++){
00209         AVStream *st = s->streams[i];
00210         AVIStream *ast = st->priv_data;
00211         int n= st->nb_index_entries;
00212         int max= ast->sample_size;
00213         int64_t pos, size, ts;
00214 
00215         if(n != 1 || ast->sample_size==0)
00216             continue;
00217 
00218         while(max < 1024) max+=max;
00219 
00220         pos= st->index_entries[0].pos;
00221         size= st->index_entries[0].size;
00222         ts= st->index_entries[0].timestamp;
00223 
00224         for(j=0; j<size; j+=max){
00225             av_add_index_entry(st, pos+j, ts + j/ast->sample_size, FFMIN(max, size-j), 0, AVINDEX_KEYFRAME);
00226         }
00227     }
00228 }
00229 
00230 static int avi_read_tag(AVFormatContext *s, const char *key, unsigned int size)
00231 {
00232     ByteIOContext *pb = s->pb;
00233     uint8_t value[1024];
00234 
00235     int64_t i = url_ftell(pb);
00236     size += (size & 1);
00237     get_strz(pb, value, sizeof(value));
00238     url_fseek(pb, i+size, SEEK_SET);
00239 
00240     return av_metadata_set(&s->metadata, key, value);
00241 }
00242 
00243 static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap)
00244 {
00245     AVIContext *avi = s->priv_data;
00246     ByteIOContext *pb = s->pb;
00247     unsigned int tag, tag1, handler;
00248     int codec_type, stream_index, frame_period, bit_rate;
00249     unsigned int size, nb_frames;
00250     int i;
00251     AVStream *st;
00252     AVIStream *ast = NULL;
00253     int avih_width=0, avih_height=0;
00254     int amv_file_format=0;
00255 
00256     avi->stream_index= -1;
00257 
00258     if (get_riff(s, pb) < 0)
00259         return -1;
00260 
00261     avi->fsize = url_fsize(pb);
00262     if(avi->fsize<=0)
00263         avi->fsize= avi->riff_end;
00264 
00265     /* first list tag */
00266     stream_index = -1;
00267     codec_type = -1;
00268     frame_period = 0;
00269     for(;;) {
00270         if (url_feof(pb))
00271             goto fail;
00272         tag = get_le32(pb);
00273         size = get_le32(pb);
00274 #ifdef DEBUG
00275         print_tag("tag", tag, size);
00276 #endif
00277 
00278         switch(tag) {
00279         case MKTAG('L', 'I', 'S', 'T'):
00280             /* Ignored, except at start of video packets. */
00281             tag1 = get_le32(pb);
00282 #ifdef DEBUG
00283             print_tag("list", tag1, 0);
00284 #endif
00285             if (tag1 == MKTAG('m', 'o', 'v', 'i')) {
00286                 avi->movi_list = url_ftell(pb) - 4;
00287                 if(size) avi->movi_end = avi->movi_list + size + (size & 1);
00288                 else     avi->movi_end = url_fsize(pb);
00289 #ifdef DEBUG
00290                 printf("movi end=%"PRIx64"\n", avi->movi_end);
00291 #endif
00292                 goto end_of_header;
00293             }
00294             break;
00295         case MKTAG('d', 'm', 'l', 'h'):
00296             avi->is_odml = 1;
00297             url_fskip(pb, size + (size & 1));
00298             break;
00299         case MKTAG('a', 'm', 'v', 'h'):
00300             amv_file_format=1;
00301         case MKTAG('a', 'v', 'i', 'h'):
00302             /* AVI header */
00303             /* using frame_period is bad idea */
00304             frame_period = get_le32(pb);
00305             bit_rate = get_le32(pb) * 8;
00306             get_le32(pb);
00307             avi->non_interleaved |= get_le32(pb) & AVIF_MUSTUSEINDEX;
00308 
00309             url_fskip(pb, 2 * 4);
00310             get_le32(pb);
00311             get_le32(pb);
00312             avih_width=get_le32(pb);
00313             avih_height=get_le32(pb);
00314 
00315             url_fskip(pb, size - 10 * 4);
00316             break;
00317         case MKTAG('s', 't', 'r', 'h'):
00318             /* stream header */
00319 
00320             tag1 = get_le32(pb);
00321             handler = get_le32(pb); /* codec tag */
00322 
00323             if(tag1 == MKTAG('p', 'a', 'd', 's')){
00324                 url_fskip(pb, size - 8);
00325                 break;
00326             }else{
00327                 stream_index++;
00328                 st = av_new_stream(s, stream_index);
00329                 if (!st)
00330                     goto fail;
00331 
00332                 ast = av_mallocz(sizeof(AVIStream));
00333                 if (!ast)
00334                     goto fail;
00335                 st->priv_data = ast;
00336             }
00337             if(amv_file_format)
00338                 tag1 = stream_index ? MKTAG('a','u','d','s') : MKTAG('v','i','d','s');
00339 
00340 #ifdef DEBUG
00341             print_tag("strh", tag1, -1);
00342 #endif
00343             if(tag1 == MKTAG('i', 'a', 'v', 's') || tag1 == MKTAG('i', 'v', 'a', 's')){
00344                 int64_t dv_dur;
00345 
00346                 /*
00347                  * After some consideration -- I don't think we
00348                  * have to support anything but DV in type1 AVIs.
00349                  */
00350                 if (s->nb_streams != 1)
00351                     goto fail;
00352 
00353                 if (handler != MKTAG('d', 'v', 's', 'd') &&
00354                     handler != MKTAG('d', 'v', 'h', 'd') &&
00355                     handler != MKTAG('d', 'v', 's', 'l'))
00356                    goto fail;
00357 
00358                 ast = s->streams[0]->priv_data;
00359                 av_freep(&s->streams[0]->codec->extradata);
00360                 av_freep(&s->streams[0]);
00361                 s->nb_streams = 0;
00362                 if (CONFIG_DV_DEMUXER) {
00363                     avi->dv_demux = dv_init_demux(s);
00364                     if (!avi->dv_demux)
00365                         goto fail;
00366                 }
00367                 s->streams[0]->priv_data = ast;
00368                 url_fskip(pb, 3 * 4);
00369                 ast->scale = get_le32(pb);
00370                 ast->rate = get_le32(pb);
00371                 url_fskip(pb, 4);  /* start time */
00372 
00373                 dv_dur = get_le32(pb);
00374                 if (ast->scale > 0 && ast->rate > 0 && dv_dur > 0) {
00375                     dv_dur *= AV_TIME_BASE;
00376                     s->duration = av_rescale(dv_dur, ast->scale, ast->rate);
00377                 }
00378                 /*
00379                  * else, leave duration alone; timing estimation in utils.c
00380                  *      will make a guess based on bitrate.
00381                  */
00382 
00383                 stream_index = s->nb_streams - 1;
00384                 url_fskip(pb, size - 9*4);
00385                 break;
00386             }
00387 
00388             assert(stream_index < s->nb_streams);
00389             st->codec->stream_codec_tag= handler;
00390 
00391             get_le32(pb); /* flags */
00392             get_le16(pb); /* priority */
00393             get_le16(pb); /* language */
00394             get_le32(pb); /* initial frame */
00395             ast->scale = get_le32(pb);
00396             ast->rate = get_le32(pb);
00397             if(!(ast->scale && ast->rate)){
00398                 av_log(s, AV_LOG_WARNING, "scale/rate is %u/%u which is invalid. (This file has been generated by broken software.)\n", ast->scale, ast->rate);
00399                 if(frame_period){
00400                     ast->rate = 1000000;
00401                     ast->scale = frame_period;
00402                 }else{
00403                     ast->rate = 25;
00404                     ast->scale = 1;
00405                 }
00406             }
00407             av_set_pts_info(st, 64, ast->scale, ast->rate);
00408 
00409             ast->cum_len=get_le32(pb); /* start */
00410             nb_frames = get_le32(pb);
00411 
00412             st->start_time = 0;
00413             st->duration = nb_frames;
00414             get_le32(pb); /* buffer size */
00415             get_le32(pb); /* quality */
00416             ast->sample_size = get_le32(pb); /* sample ssize */
00417             ast->cum_len *= FFMAX(1, ast->sample_size);
00418 //            av_log(s, AV_LOG_DEBUG, "%d %d %d %d\n", ast->rate, ast->scale, ast->start, ast->sample_size);
00419 
00420             switch(tag1) {
00421             case MKTAG('v', 'i', 'd', 's'):
00422                 codec_type = CODEC_TYPE_VIDEO;
00423 
00424                 ast->sample_size = 0;
00425                 break;
00426             case MKTAG('a', 'u', 'd', 's'):
00427                 codec_type = CODEC_TYPE_AUDIO;
00428                 break;
00429             case MKTAG('t', 'x', 't', 's'):
00430                 //FIXME
00431                 codec_type = CODEC_TYPE_DATA; //CODEC_TYPE_SUB ?  FIXME
00432                 break;
00433             case MKTAG('d', 'a', 't', 's'):
00434                 codec_type = CODEC_TYPE_DATA;
00435                 break;
00436             default:
00437                 av_log(s, AV_LOG_ERROR, "unknown stream type %X\n", tag1);
00438                 goto fail;
00439             }
00440             ast->frame_offset= ast->cum_len;
00441             url_fskip(pb, size - 12 * 4);
00442             break;
00443         case MKTAG('s', 't', 'r', 'f'):
00444             /* stream header */
00445             if (stream_index >= (unsigned)s->nb_streams || avi->dv_demux) {
00446                 url_fskip(pb, size);
00447             } else {
00448                 st = s->streams[stream_index];
00449                 switch(codec_type) {
00450                 case CODEC_TYPE_VIDEO:
00451                     if(amv_file_format){
00452                         st->codec->width=avih_width;
00453                         st->codec->height=avih_height;
00454                         st->codec->codec_type = CODEC_TYPE_VIDEO;
00455                         st->codec->codec_id = CODEC_ID_AMV;
00456                         url_fskip(pb, size);
00457                         break;
00458                     }
00459                     get_le32(pb); /* size */
00460                     st->codec->width = get_le32(pb);
00461                     st->codec->height = (int32_t)get_le32(pb);
00462                     get_le16(pb); /* panes */
00463                     st->codec->bits_per_coded_sample= get_le16(pb); /* depth */
00464                     tag1 = get_le32(pb);
00465                     get_le32(pb); /* ImageSize */
00466                     get_le32(pb); /* XPelsPerMeter */
00467                     get_le32(pb); /* YPelsPerMeter */
00468                     get_le32(pb); /* ClrUsed */
00469                     get_le32(pb); /* ClrImportant */
00470 
00471                     if (tag1 == MKTAG('D', 'X', 'S', 'B')) {
00472                         st->codec->codec_type = CODEC_TYPE_SUBTITLE;
00473                         st->codec->codec_tag = tag1;
00474                         st->codec->codec_id = CODEC_ID_XSUB;
00475                         break;
00476                     }
00477 
00478                     if(size > 10*4 && size<(1<<30)){
00479                         st->codec->extradata_size= size - 10*4;
00480                         st->codec->extradata= av_malloc(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
00481                         get_buffer(pb, st->codec->extradata, st->codec->extradata_size);
00482                     }
00483 
00484                     if(st->codec->extradata_size & 1) //FIXME check if the encoder really did this correctly
00485                         get_byte(pb);
00486 
00487                     /* Extract palette from extradata if bpp <= 8. */
00488                     /* This code assumes that extradata contains only palette. */
00489                     /* This is true for all paletted codecs implemented in FFmpeg. */
00490                     if (st->codec->extradata_size && (st->codec->bits_per_coded_sample <= 8)) {
00491                         st->codec->palctrl = av_mallocz(sizeof(AVPaletteControl));
00492 #ifdef WORDS_BIGENDIAN
00493                         for (i = 0; i < FFMIN(st->codec->extradata_size, AVPALETTE_SIZE)/4; i++)
00494                             st->codec->palctrl->palette[i] = bswap_32(((uint32_t*)st->codec->extradata)[i]);
00495 #else
00496                         memcpy(st->codec->palctrl->palette, st->codec->extradata,
00497                                FFMIN(st->codec->extradata_size, AVPALETTE_SIZE));
00498 #endif
00499                         st->codec->palctrl->palette_changed = 1;
00500                     }
00501 
00502 #ifdef DEBUG
00503                     print_tag("video", tag1, 0);
00504 #endif
00505                     st->codec->codec_type = CODEC_TYPE_VIDEO;
00506                     st->codec->codec_tag = tag1;
00507                     st->codec->codec_id = codec_get_id(codec_bmp_tags, tag1);
00508                     st->need_parsing = AVSTREAM_PARSE_HEADERS; // This is needed to get the pict type which is necessary for generating correct pts.
00509 
00510                     if(st->codec->codec_tag==0 && st->codec->height > 0 && st->codec->extradata_size < 1U<<30){
00511                         st->codec->extradata_size+= 9;
00512                         st->codec->extradata= av_realloc(st->codec->extradata, st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
00513                         if(st->codec->extradata)
00514                             memcpy(st->codec->extradata + st->codec->extradata_size - 9, "BottomUp", 9);
00515                     }
00516                     st->codec->height= FFABS(st->codec->height);
00517 
00518 //                    url_fskip(pb, size - 5 * 4);
00519                     break;
00520                 case CODEC_TYPE_AUDIO:
00521                     get_wav_header(pb, st->codec, size);
00522                     if(ast->sample_size && st->codec->block_align && ast->sample_size != st->codec->block_align){
00523                         av_log(s, AV_LOG_WARNING, "sample size (%d) != block align (%d)\n", ast->sample_size, st->codec->block_align);
00524                         ast->sample_size= st->codec->block_align;
00525                     }
00526                     if (size%2) /* 2-aligned (fix for Stargate SG-1 - 3x18 - Shades of Grey.avi) */
00527                         url_fskip(pb, 1);
00528                     /* Force parsing as several audio frames can be in
00529                      * one packet and timestamps refer to packet start. */
00530                     st->need_parsing = AVSTREAM_PARSE_TIMESTAMPS;
00531                     /* ADTS header is in extradata, AAC without header must be
00532                      * stored as exact frames. Parser not needed and it will
00533                      * fail. */
00534                     if (st->codec->codec_id == CODEC_ID_AAC && st->codec->extradata_size)
00535                         st->need_parsing = AVSTREAM_PARSE_NONE;
00536                     /* AVI files with Xan DPCM audio (wrongly) declare PCM
00537                      * audio in the header but have Axan as stream_code_tag. */
00538                     if (st->codec->stream_codec_tag == AV_RL32("Axan")){
00539                         st->codec->codec_id  = CODEC_ID_XAN_DPCM;
00540                         st->codec->codec_tag = 0;
00541                     }
00542                     if (amv_file_format)
00543                         st->codec->codec_id  = CODEC_ID_ADPCM_IMA_AMV;
00544                     break;
00545                 default:
00546                     st->codec->codec_type = CODEC_TYPE_DATA;
00547                     st->codec->codec_id= CODEC_ID_NONE;
00548                     st->codec->codec_tag= 0;
00549                     url_fskip(pb, size);
00550                     break;
00551                 }
00552             }
00553             break;
00554         case MKTAG('i', 'n', 'd', 'x'):
00555             i= url_ftell(pb);
00556             if(!url_is_streamed(pb) && !(s->flags & AVFMT_FLAG_IGNIDX)){
00557                 read_braindead_odml_indx(s, 0);
00558             }
00559             url_fseek(pb, i+size, SEEK_SET);
00560             break;
00561         case MKTAG('v', 'p', 'r', 'p'):
00562             if(stream_index < (unsigned)s->nb_streams && size > 9*4){
00563                 AVRational active, active_aspect;
00564 
00565                 st = s->streams[stream_index];
00566                 get_le32(pb);
00567                 get_le32(pb);
00568                 get_le32(pb);
00569                 get_le32(pb);
00570                 get_le32(pb);
00571 
00572                 active_aspect.den= get_le16(pb);
00573                 active_aspect.num= get_le16(pb);
00574                 active.num       = get_le32(pb);
00575                 active.den       = get_le32(pb);
00576                 get_le32(pb); //nbFieldsPerFrame
00577 
00578                 if(active_aspect.num && active_aspect.den && active.num && active.den){
00579                     st->sample_aspect_ratio= av_div_q(active_aspect, active);
00580 //av_log(s, AV_LOG_ERROR, "vprp %d/%d %d/%d\n", active_aspect.num, active_aspect.den, active.num, active.den);
00581                 }
00582                 size -= 9*4;
00583             }
00584             url_fseek(pb, size, SEEK_CUR);
00585             break;
00586         case MKTAG('I', 'N', 'A', 'M'):
00587             avi_read_tag(s, "Title", size);
00588             break;
00589         case MKTAG('I', 'A', 'R', 'T'):
00590             avi_read_tag(s, "Artist", size);
00591             break;
00592         case MKTAG('I', 'C', 'O', 'P'):
00593             avi_read_tag(s, "Copyright", size);
00594             break;
00595         case MKTAG('I', 'C', 'M', 'T'):
00596             avi_read_tag(s, "Comment", size);
00597             break;
00598         case MKTAG('I', 'G', 'N', 'R'):
00599             avi_read_tag(s, "Genre", size);
00600             break;
00601         case MKTAG('I', 'P', 'R', 'D'):
00602             avi_read_tag(s, "Album", size);
00603             break;
00604         case MKTAG('I', 'P', 'R', 'T'):
00605             avi_read_tag(s, "Track", size);
00606             break;
00607         default:
00608             if(size > 1000000){
00609                 av_log(s, AV_LOG_ERROR, "Something went wrong during header parsing, "
00610                                         "I will ignore it and try to continue anyway.\n");
00611                 avi->movi_list = url_ftell(pb) - 4;
00612                 avi->movi_end  = url_fsize(pb);
00613                 goto end_of_header;
00614             }
00615             /* skip tag */
00616             size += (size & 1);
00617             url_fskip(pb, size);
00618             break;
00619         }
00620     }
00621  end_of_header:
00622     /* check stream number */
00623     if (stream_index != s->nb_streams - 1) {
00624     fail:
00625         return -1;
00626     }
00627 
00628     if(!avi->index_loaded && !url_is_streamed(pb))
00629         avi_load_index(s);
00630     avi->index_loaded = 1;
00631     avi->non_interleaved |= guess_ni_flag(s);
00632     if(avi->non_interleaved) {
00633         av_log(s, AV_LOG_INFO, "non-interleaved AVI\n");
00634         clean_index(s);
00635     }
00636 
00637     return 0;
00638 }
00639 
00640 static int get_stream_idx(int *d){
00641     if(    d[0] >= '0' && d[0] <= '9'
00642         && d[1] >= '0' && d[1] <= '9'){
00643         return (d[0] - '0') * 10 + (d[1] - '0');
00644     }else{
00645         return 100; //invalid stream ID
00646     }
00647 }
00648 
00649 static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)
00650 {
00651     AVIContext *avi = s->priv_data;
00652     ByteIOContext *pb = s->pb;
00653     int n, d[8];
00654     unsigned int size;
00655     int64_t i, sync;
00656     void* dstr;
00657 
00658     if (CONFIG_DV_DEMUXER && avi->dv_demux) {
00659         int size = dv_get_packet(avi->dv_demux, pkt);
00660         if (size >= 0)
00661             return size;
00662     }
00663 
00664     if(avi->non_interleaved){
00665         int best_stream_index = 0;
00666         AVStream *best_st= NULL;
00667         AVIStream *best_ast;
00668         int64_t best_ts= INT64_MAX;
00669         int i;
00670 
00671         for(i=0; i<s->nb_streams; i++){
00672             AVStream *st = s->streams[i];
00673             AVIStream *ast = st->priv_data;
00674             int64_t ts= ast->frame_offset;
00675 
00676             if(ast->sample_size)
00677                 ts /= ast->sample_size;
00678             ts= av_rescale(ts, AV_TIME_BASE * (int64_t)st->time_base.num, st->time_base.den);
00679 
00680 //            av_log(s, AV_LOG_DEBUG, "%"PRId64" %d/%d %"PRId64"\n", ts, st->time_base.num, st->time_base.den, ast->frame_offset);
00681             if(ts < best_ts && st->nb_index_entries){
00682                 best_ts= ts;
00683                 best_st= st;
00684                 best_stream_index= i;
00685             }
00686         }
00687         if(!best_st)
00688             return -1;
00689 
00690         best_ast = best_st->priv_data;
00691         best_ts= av_rescale(best_ts, best_st->time_base.den, AV_TIME_BASE * (int64_t)best_st->time_base.num); //FIXME a little ugly
00692         if(best_ast->remaining)
00693             i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
00694         else{
00695             i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY);
00696             if(i>=0)
00697                 best_ast->frame_offset= best_st->index_entries[i].timestamp
00698                                       * FFMAX(1, best_ast->sample_size);
00699         }
00700 
00701 //        av_log(s, AV_LOG_DEBUG, "%d\n", i);
00702         if(i>=0){
00703             int64_t pos= best_st->index_entries[i].pos;
00704             pos += best_ast->packet_size - best_ast->remaining;
00705             url_fseek(s->pb, pos + 8, SEEK_SET);
00706 //        av_log(s, AV_LOG_DEBUG, "pos=%"PRId64"\n", pos);
00707 
00708             assert(best_ast->remaining <= best_ast->packet_size);
00709 
00710             avi->stream_index= best_stream_index;
00711             if(!best_ast->remaining)
00712                 best_ast->packet_size=
00713                 best_ast->remaining= best_st->index_entries[i].size;
00714         }
00715     }
00716 
00717 resync:
00718     if(avi->stream_index >= 0){
00719         AVStream *st= s->streams[ avi->stream_index ];
00720         AVIStream *ast= st->priv_data;
00721         int size, err;
00722 
00723         if(ast->sample_size <= 1) // minorityreport.AVI block_align=1024 sample_size=1 IMA-ADPCM
00724             size= INT_MAX;
00725         else if(ast->sample_size < 32)
00726             size= 64*ast->sample_size;
00727         else
00728             size= ast->sample_size;
00729 
00730         if(size > ast->remaining)
00731             size= ast->remaining;
00732         avi->last_pkt_pos= url_ftell(pb);
00733         err= av_get_packet(pb, pkt, size);
00734         if(err<0)
00735             return err;
00736 
00737         if(ast->has_pal && pkt->data && pkt->size<(unsigned)INT_MAX/2){
00738             void *ptr= av_realloc(pkt->data, pkt->size + 4*256 + FF_INPUT_BUFFER_PADDING_SIZE);
00739             if(ptr){
00740             ast->has_pal=0;
00741             pkt->size += 4*256;
00742             pkt->data= ptr;
00743                 memcpy(pkt->data + pkt->size - 4*256, ast->pal, 4*256);
00744             }else
00745                 av_log(s, AV_LOG_ERROR, "Failed to append palette\n");
00746         }
00747 
00748         if (CONFIG_DV_DEMUXER && avi->dv_demux) {
00749             dstr = pkt->destruct;
00750             size = dv_produce_packet(avi->dv_demux, pkt,
00751                                     pkt->data, pkt->size);
00752             pkt->destruct = dstr;
00753             pkt->flags |= PKT_FLAG_KEY;
00754         } else {
00755             /* XXX: How to handle B-frames in AVI? */
00756             pkt->dts = ast->frame_offset;
00757 //                pkt->dts += ast->start;
00758             if(ast->sample_size)
00759                 pkt->dts /= ast->sample_size;
00760 //av_log(s, AV_LOG_DEBUG, "dts:%"PRId64" offset:%"PRId64" %d/%d smpl_siz:%d base:%d st:%d size:%d\n", pkt->dts, ast->frame_offset, ast->scale, ast->rate, ast->sample_size, AV_TIME_BASE, avi->stream_index, size);
00761             pkt->stream_index = avi->stream_index;
00762 
00763             if (st->codec->codec_type == CODEC_TYPE_VIDEO) {
00764                 AVIndexEntry *e;
00765                 int index;
00766                 assert(st->index_entries);
00767 
00768                 index= av_index_search_timestamp(st, pkt->dts, 0);
00769                 e= &st->index_entries[index];
00770 
00771                 if(index >= 0 && e->timestamp == ast->frame_offset){
00772                     if (e->flags & AVINDEX_KEYFRAME)
00773                         pkt->flags |= PKT_FLAG_KEY;
00774                 }
00775             } else {
00776                 pkt->flags |= PKT_FLAG_KEY;
00777             }
00778             if(ast->sample_size)
00779                 ast->frame_offset += pkt->size;
00780             else
00781                 ast->frame_offset++;
00782         }
00783         ast->remaining -= size;
00784         if(!ast->remaining){
00785             avi->stream_index= -1;
00786             ast->packet_size= 0;
00787         }
00788 
00789         return size;
00790     }
00791 
00792     memset(d, -1, sizeof(int)*8);
00793     for(i=sync=url_ftell(pb); !url_feof(pb); i++) {
00794         int j;
00795 
00796         for(j=0; j<7; j++)
00797             d[j]= d[j+1];
00798         d[7]= get_byte(pb);
00799 
00800         size= d[4] + (d[5]<<8) + (d[6]<<16) + (d[7]<<24);
00801 
00802         n= get_stream_idx(d+2);
00803 //av_log(s, AV_LOG_DEBUG, "%X %X %X %X %X %X %X %X %"PRId64" %d %d\n", d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7], i, size, n);
00804         if(i + (uint64_t)size > avi->fsize || d[0]<0)
00805             continue;
00806 
00807         //parse ix##
00808         if(  (d[0] == 'i' && d[1] == 'x' && n < s->nb_streams)
00809         //parse JUNK
00810            ||(d[0] == 'J' && d[1] == 'U' && d[2] == 'N' && d[3] == 'K')
00811            ||(d[0] == 'i' && d[1] == 'd' && d[2] == 'x' && d[3] == '1')){
00812             url_fskip(pb, size);
00813 //av_log(s, AV_LOG_DEBUG, "SKIP\n");
00814             goto resync;
00815         }
00816 
00817         n= get_stream_idx(d);
00818 
00819         if(!((i-avi->last_pkt_pos)&1) && get_stream_idx(d+1) < s->nb_streams)
00820             continue;
00821 
00822         //parse ##dc/##wb
00823         if(n < s->nb_streams){
00824             AVStream *st;
00825             AVIStream *ast;
00826             st = s->streams[n];
00827             ast = st->priv_data;
00828 
00829             if(s->nb_streams>=2){
00830                 AVStream *st1  = s->streams[1];
00831                 AVIStream *ast1= st1->priv_data;
00832                 //workaround for broken small-file-bug402.avi
00833                 if(   d[2] == 'w' && d[3] == 'b'
00834                    && n==0
00835                    && st ->codec->codec_type == CODEC_TYPE_VIDEO
00836                    && st1->codec->codec_type == CODEC_TYPE_AUDIO
00837                    && ast->prefix == 'd'*256+'c'
00838                    && (d[2]*256+d[3] == ast1->prefix || !ast1->prefix_count)
00839                   ){
00840                     n=1;
00841                     st = st1;
00842                     ast = ast1;
00843                     av_log(s, AV_LOG_WARNING, "Invalid stream + prefix combination, assuming audio.\n");
00844                 }
00845             }
00846 
00847 
00848             if(   (st->discard >= AVDISCARD_DEFAULT && size==0)
00849                /*|| (st->discard >= AVDISCARD_NONKEY && !(pkt->flags & PKT_FLAG_KEY))*/ //FIXME needs a little reordering
00850                || st->discard >= AVDISCARD_ALL){
00851                 if(ast->sample_size) ast->frame_offset += pkt->size;
00852                 else                 ast->frame_offset++;
00853                 url_fskip(pb, size);
00854                 goto resync;
00855             }
00856 
00857             if (d[2] == 'p' && d[3] == 'c' && size<=4*256+4) {
00858                 int k = get_byte(pb);
00859                 int last = (k + get_byte(pb) - 1) & 0xFF;
00860 
00861                 get_le16(pb); //flags
00862 
00863                 for (; k <= last; k++)
00864                     ast->pal[k] = get_be32(pb)>>8;// b + (g << 8) + (r << 16);
00865                 ast->has_pal= 1;
00866                 goto resync;
00867             } else if(   ((ast->prefix_count<5 || sync+9 > i) && d[2]<128 && d[3]<128) ||
00868                          d[2]*256+d[3] == ast->prefix /*||
00869                          (d[2] == 'd' && d[3] == 'c') ||
00870                          (d[2] == 'w' && d[3] == 'b')*/) {
00871 
00872 //av_log(s, AV_LOG_DEBUG, "OK\n");
00873                 if(d[2]*256+d[3] == ast->prefix)
00874                     ast->prefix_count++;
00875                 else{
00876                     ast->prefix= d[2]*256+d[3];
00877                     ast->prefix_count= 0;
00878                 }
00879 
00880                 avi->stream_index= n;
00881                 ast->packet_size= size + 8;
00882                 ast->remaining= size;
00883 
00884                 {
00885                     uint64_t pos= url_ftell(pb) - 8;
00886                     if(!st->index_entries || !st->nb_index_entries || st->index_entries[st->nb_index_entries - 1].pos < pos){
00887                         av_add_index_entry(st, pos, ast->frame_offset / FFMAX(1, ast->sample_size), size, 0, AVINDEX_KEYFRAME);
00888                     }
00889                 }
00890                 goto resync;
00891             }
00892         }
00893     }
00894 
00895     return AVERROR_EOF;
00896 }
00897 
00898 /* XXX: We make the implicit supposition that the positions are sorted
00899    for each stream. */
00900 static int avi_read_idx1(AVFormatContext *s, int size)
00901 {
00902     AVIContext *avi = s->priv_data;
00903     ByteIOContext *pb = s->pb;
00904     int nb_index_entries, i;
00905     AVStream *st;
00906     AVIStream *ast;
00907     unsigned int index, tag, flags, pos, len;
00908     unsigned last_pos= -1;
00909 
00910     nb_index_entries = size / 16;
00911     if (nb_index_entries <= 0)
00912         return -1;
00913 
00914     /* Read the entries and sort them in each stream component. */
00915     for(i = 0; i < nb_index_entries; i++) {
00916         tag = get_le32(pb);
00917         flags = get_le32(pb);
00918         pos = get_le32(pb);
00919         len = get_le32(pb);
00920 #if defined(DEBUG_SEEK)
00921         av_log(s, AV_LOG_DEBUG, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/",
00922                i, tag, flags, pos, len);
00923 #endif
00924         if(i==0 && pos > avi->movi_list)
00925             avi->movi_list= 0; //FIXME better check
00926         pos += avi->movi_list;
00927 
00928         index = ((tag & 0xff) - '0') * 10;
00929         index += ((tag >> 8) & 0xff) - '0';
00930         if (index >= s->nb_streams)
00931             continue;
00932         st = s->streams[index];
00933         ast = st->priv_data;
00934 
00935 #if defined(DEBUG_SEEK)
00936         av_log(s, AV_LOG_DEBUG, "%d cum_len=%"PRId64"\n", len, ast->cum_len);
00937 #endif
00938         if(url_feof(pb))
00939             return -1;
00940 
00941         if(last_pos == pos)
00942             avi->non_interleaved= 1;
00943         else
00944             av_add_index_entry(st, pos, ast->cum_len / FFMAX(1, ast->sample_size), len, 0, (flags&AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);
00945         if(ast->sample_size)
00946             ast->cum_len += len;
00947         else
00948             ast->cum_len ++;
00949         last_pos= pos;
00950     }
00951     return 0;
00952 }
00953 
00954 static int guess_ni_flag(AVFormatContext *s){
00955     int i;
00956     int64_t last_start=0;
00957     int64_t first_end= INT64_MAX;
00958 
00959     for(i=0; i<s->nb_streams; i++){
00960         AVStream *st = s->streams[i];
00961         int n= st->nb_index_entries;
00962 
00963         if(n <= 0)
00964             continue;
00965 
00966         if(st->index_entries[0].pos > last_start)
00967             last_start= st->index_entries[0].pos;
00968         if(st->index_entries[n-1].pos < first_end)
00969             first_end= st->index_entries[n-1].pos;
00970     }
00971     return last_start > first_end;
00972 }
00973 
00974 static int avi_load_index(AVFormatContext *s)
00975 {
00976     AVIContext *avi = s->priv_data;
00977     ByteIOContext *pb = s->pb;
00978     uint32_t tag, size;
00979     int64_t pos= url_ftell(pb);
00980 
00981     url_fseek(pb, avi->movi_end, SEEK_SET);
00982 #ifdef DEBUG_SEEK
00983     printf("movi_end=0x%"PRIx64"\n", avi->movi_end);
00984 #endif
00985     for(;;) {
00986         if (url_feof(pb))
00987             break;
00988         tag = get_le32(pb);
00989         size = get_le32(pb);
00990 #ifdef DEBUG_SEEK
00991         printf("tag=%c%c%c%c size=0x%x\n",
00992                tag & 0xff,
00993                (tag >> 8) & 0xff,
00994                (tag >> 16) & 0xff,
00995                (tag >> 24) & 0xff,
00996                size);
00997 #endif
00998         switch(tag) {
00999         case MKTAG('i', 'd', 'x', '1'):
01000             if (avi_read_idx1(s, size) < 0)
01001                 goto skip;
01002             else
01003                 goto the_end;
01004             break;
01005         default:
01006         skip:
01007             size += (size & 1);
01008             url_fskip(pb, size);
01009             break;
01010         }
01011     }
01012  the_end:
01013     url_fseek(pb, pos, SEEK_SET);
01014     return 0;
01015 }
01016 
01017 static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
01018 {
01019     AVIContext *avi = s->priv_data;
01020     AVStream *st;
01021     int i, index;
01022     int64_t pos;
01023 
01024     if (!avi->index_loaded) {
01025         /* we only load the index on demand */
01026         avi_load_index(s);
01027         avi->index_loaded = 1;
01028     }
01029     assert(stream_index>= 0);
01030 
01031     st = s->streams[stream_index];
01032     index= av_index_search_timestamp(st, timestamp, flags);
01033     if(index<0)
01034         return -1;
01035 
01036     /* find the position */
01037     pos = st->index_entries[index].pos;
01038     timestamp = st->index_entries[index].timestamp;
01039 
01040 //    av_log(s, AV_LOG_DEBUG, "XX %"PRId64" %d %"PRId64"\n", timestamp, index, st->index_entries[index].timestamp);
01041 
01042     if (CONFIG_DV_DEMUXER && avi->dv_demux) {
01043         /* One and only one real stream for DV in AVI, and it has video  */
01044         /* offsets. Calling with other stream indexes should have failed */
01045         /* the av_index_search_timestamp call above.                     */
01046         assert(stream_index == 0);
01047 
01048         /* Feed the DV video stream version of the timestamp to the */
01049         /* DV demux so it can synthesize correct timestamps.        */
01050         dv_offset_reset(avi->dv_demux, timestamp);
01051 
01052         url_fseek(s->pb, pos, SEEK_SET);
01053         avi->stream_index= -1;
01054         return 0;
01055     }
01056 
01057     for(i = 0; i < s->nb_streams; i++) {
01058         AVStream *st2 = s->streams[i];
01059         AVIStream *ast2 = st2->priv_data;
01060 
01061         ast2->packet_size=
01062         ast2->remaining= 0;
01063 
01064         if (st2->nb_index_entries <= 0)
01065             continue;
01066 
01067 //        assert(st2->codec->block_align);
01068         assert((int64_t)st2->time_base.num*ast2->rate == (int64_t)st2->time_base.den*ast2->scale);
01069         index = av_index_search_timestamp(
01070                 st2,
01071                 av_rescale(timestamp, st2->time_base.den*(int64_t)st->time_base.num, st->time_base.den * (int64_t)st2->time_base.num),
01072                 flags | AVSEEK_FLAG_BACKWARD);
01073         if(index<0)
01074             index=0;
01075 
01076         if(!avi->non_interleaved){
01077             while(index>0 && st2->index_entries[index].pos > pos)
01078                 index--;
01079             while(index+1 < st2->nb_index_entries && st2->index_entries[index].pos < pos)
01080                 index++;
01081         }
01082 
01083 //        av_log(s, AV_LOG_DEBUG, "%"PRId64" %d %"PRId64"\n", timestamp, index, st2->index_entries[index].timestamp);
01084         /* extract the current frame number */
01085         ast2->frame_offset = st2->index_entries[index].timestamp;
01086         if(ast2->sample_size)
01087             ast2->frame_offset *=ast2->sample_size;
01088     }
01089 
01090     /* do the seek */
01091     url_fseek(s->pb, pos, SEEK_SET);
01092     avi->stream_index= -1;
01093     return 0;
01094 }
01095 
01096 static int avi_read_close(AVFormatContext *s)
01097 {
01098     int i;
01099     AVIContext *avi = s->priv_data;
01100 
01101     for(i=0;i<s->nb_streams;i++) {
01102         AVStream *st = s->streams[i];
01103         av_free(st->codec->palctrl);
01104     }
01105 
01106     if (avi->dv_demux)
01107         av_free(avi->dv_demux);
01108 
01109     return 0;
01110 }
01111 
01112 static int avi_probe(AVProbeData *p)
01113 {
01114     int i;
01115 
01116     /* check file header */
01117     for(i=0; avi_headers[i][0]; i++)
01118         if(!memcmp(p->buf  , avi_headers[i]  , 4) &&
01119            !memcmp(p->buf+8, avi_headers[i]+4, 4))
01120             return AVPROBE_SCORE_MAX;
01121 
01122     return 0;
01123 }
01124 
01125 AVInputFormat avi_demuxer = {
01126     "avi",
01127     NULL_IF_CONFIG_SMALL("AVI format"),
01128     sizeof(AVIContext),
01129     avi_probe,
01130     avi_read_header,
01131     avi_read_packet,
01132     avi_read_close,
01133     avi_read_seek,
01134 };