FFmpeg: libavformat/nutdec.c Source File

00001 /*
00002  * "NUT" Container Format demuxer
00003  * Copyright (c) 2004-2006 Michael Niedermayer
00004  * Copyright (c) 2003 Alex Beregszaszi
00005  *
00006  * This file is part of FFmpeg.
00007  *
00008  * FFmpeg is free software; you can redistribute it and/or
00009  * modify it under the terms of the GNU Lesser General Public
00010  * License as published by the Free Software Foundation; either
00011  * version 2.1 of the License, or (at your option) any later version.
00012  *
00013  * FFmpeg is distributed in the hope that it will be useful,
00014  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00016  * Lesser General Public License for more details.
00017  *
00018  * You should have received a copy of the GNU Lesser General Public
00019  * License along with FFmpeg; if not, write to the Free Software
00020  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00021  */
00022 
00023 #include "libavutil/avstring.h"
00024 #include "libavutil/avassert.h"
00025 #include "libavutil/bswap.h"
00026 #include "libavutil/dict.h"
00027 #include "libavutil/mathematics.h"
00028 #include "libavutil/tree.h"
00029 #include "avio_internal.h"
00030 #include "nut.h"
00031 
00032 #define NUT_MAX_STREAMS 256    /* arbitrary sanity check value */
00033 
00034 static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index,
00035                                   int64_t *pos_arg, int64_t pos_limit);
00036 
00037 static int get_str(AVIOContext *bc, char *string, unsigned int maxlen)
00038 {
00039     unsigned int len = ffio_read_varlen(bc);
00040 
00041     if (len && maxlen)
00042         avio_read(bc, string, FFMIN(len, maxlen));
00043     while (len > maxlen) {
00044         avio_r8(bc);
00045         len--;
00046     }
00047 
00048     if (maxlen)
00049         string[FFMIN(len, maxlen - 1)] = 0;
00050 
00051     if (maxlen == len)
00052         return -1;
00053     else
00054         return 0;
00055 }
00056 
00057 static int64_t get_s(AVIOContext *bc)
00058 {
00059     int64_t v = ffio_read_varlen(bc) + 1;
00060 
00061     if (v & 1)
00062         return -(v >> 1);
00063     else
00064         return  (v >> 1);
00065 }
00066 
00067 static uint64_t get_fourcc(AVIOContext *bc)
00068 {
00069     unsigned int len = ffio_read_varlen(bc);
00070 
00071     if (len == 2)
00072         return avio_rl16(bc);
00073     else if (len == 4)
00074         return avio_rl32(bc);
00075     else
00076         return -1;
00077 }
00078 
00079 #ifdef TRACE
00080 static inline uint64_t get_v_trace(AVIOContext *bc, const char *file,
00081                                    const char *func, int line)
00082 {
00083     uint64_t v = ffio_read_varlen(bc);
00084 
00085     av_log(NULL, AV_LOG_DEBUG, "get_v %5"PRId64" / %"PRIX64" in %s %s:%d\n",
00086            v, v, file, func, line);
00087     return v;
00088 }
00089 
00090 static inline int64_t get_s_trace(AVIOContext *bc, const char *file,
00091                                   const char *func, int line)
00092 {
00093     int64_t v = get_s(bc);
00094 
00095     av_log(NULL, AV_LOG_DEBUG, "get_s %5"PRId64" / %"PRIX64" in %s %s:%d\n",
00096            v, v, file, func, line);
00097     return v;
00098 }
00099 
00100 static inline uint64_t get_vb_trace(AVIOContext *bc, char *file,
00101                                     char *func, int line)
00102 {
00103     uint64_t v = get_vb(bc);
00104 
00105     av_log(NULL, AV_LOG_DEBUG, "get_vb %5"PRId64" / %"PRIX64" in %s %s:%d\n",
00106            v, v, file, func, line);
00107     return v;
00108 }
00109 #define ffio_read_varlen(bc) get_v_trace(bc,  __FILE__, __PRETTY_FUNCTION__, __LINE__)
00110 #define get_s(bc)            get_s_trace(bc,  __FILE__, __PRETTY_FUNCTION__, __LINE__)
00111 #define get_vb(bc)           get_vb_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
00112 #endif
00113 
00114 static int get_packetheader(NUTContext *nut, AVIOContext *bc,
00115                             int calculate_checksum, uint64_t startcode)
00116 {
00117     int64_t size;
00118 //    start = avio_tell(bc) - 8;
00119 
00120     startcode = av_be2ne64(startcode);
00121     startcode = ff_crc04C11DB7_update(0, (uint8_t*) &startcode, 8);
00122 
00123     ffio_init_checksum(bc, ff_crc04C11DB7_update, startcode);
00124     size = ffio_read_varlen(bc);
00125     if (size > 4096)
00126         avio_rb32(bc);
00127     if (ffio_get_checksum(bc) && size > 4096)
00128         return -1;
00129 
00130     ffio_init_checksum(bc, calculate_checksum ? ff_crc04C11DB7_update : NULL, 0);
00131 
00132     return size;
00133 }
00134 
00135 static uint64_t find_any_startcode(AVIOContext *bc, int64_t pos)
00136 {
00137     uint64_t state = 0;
00138 
00139     if (pos >= 0)
00140         /* Note, this may fail if the stream is not seekable, but that should
00141          * not matter, as in this case we simply start where we currently are */
00142         avio_seek(bc, pos, SEEK_SET);
00143     while (!url_feof(bc)) {
00144         state = (state << 8) | avio_r8(bc);
00145         if ((state >> 56) != 'N')
00146             continue;
00147         switch (state) {
00148         case MAIN_STARTCODE:
00149         case STREAM_STARTCODE:
00150         case SYNCPOINT_STARTCODE:
00151         case INFO_STARTCODE:
00152         case INDEX_STARTCODE:
00153             return state;
00154         }
00155     }
00156 
00157     return 0;
00158 }
00159 
00166 static int64_t find_startcode(AVIOContext *bc, uint64_t code, int64_t pos)
00167 {
00168     for (;;) {
00169         uint64_t startcode = find_any_startcode(bc, pos);
00170         if (startcode == code)
00171             return avio_tell(bc) - 8;
00172         else if (startcode == 0)
00173             return -1;
00174         pos = -1;
00175     }
00176 }
00177 
00178 static int nut_probe(AVProbeData *p)
00179 {
00180     int i;
00181     uint64_t code = 0;
00182 
00183     for (i = 0; i < p->buf_size; i++) {
00184         code = (code << 8) | p->buf[i];
00185         if (code == MAIN_STARTCODE)
00186             return AVPROBE_SCORE_MAX;
00187     }
00188     return 0;
00189 }
00190 
00191 #define GET_V(dst, check)                                                 \
00192     tmp = ffio_read_varlen(bc);                                           \
00193     if (!(check)) {                                                       \
00194         av_log(s, AV_LOG_ERROR, "Error " #dst " is (%"PRId64")\n", tmp);  \
00195         return -1;                                                        \
00196     }                                                                     \
00197     dst = tmp;
00198 
00199 static int skip_reserved(AVIOContext *bc, int64_t pos)
00200 {
00201     pos -= avio_tell(bc);
00202     if (pos < 0) {
00203         avio_seek(bc, pos, SEEK_CUR);
00204         return -1;
00205     } else {
00206         while (pos--)
00207             avio_r8(bc);
00208         return 0;
00209     }
00210 }
00211 
00212 static int decode_main_header(NUTContext *nut)
00213 {
00214     AVFormatContext *s = nut->avf;
00215     AVIOContext *bc    = s->pb;
00216     uint64_t tmp, end;
00217     unsigned int stream_count;
00218     int i, j, count;
00219     int tmp_stream, tmp_mul, tmp_pts, tmp_size, tmp_res, tmp_head_idx;
00220 
00221     end  = get_packetheader(nut, bc, 1, MAIN_STARTCODE);
00222     end += avio_tell(bc);
00223 
00224     GET_V(tmp, tmp >= 2 && tmp <= 3)
00225     GET_V(stream_count, tmp > 0 && tmp <= NUT_MAX_STREAMS)
00226 
00227     nut->max_distance = ffio_read_varlen(bc);
00228     if (nut->max_distance > 65536) {
00229         av_log(s, AV_LOG_DEBUG, "max_distance %d\n", nut->max_distance);
00230         nut->max_distance = 65536;
00231     }
00232 
00233     GET_V(nut->time_base_count, tmp > 0 && tmp < INT_MAX / sizeof(AVRational))
00234     nut->time_base = av_malloc(nut->time_base_count * sizeof(AVRational));
00235 
00236     for (i = 0; i < nut->time_base_count; i++) {
00237         GET_V(nut->time_base[i].num, tmp > 0 && tmp < (1ULL << 31))
00238         GET_V(nut->time_base[i].den, tmp > 0 && tmp < (1ULL << 31))
00239         if (av_gcd(nut->time_base[i].num, nut->time_base[i].den) != 1) {
00240             av_log(s, AV_LOG_ERROR, "time base invalid\n");
00241             return AVERROR_INVALIDDATA;
00242         }
00243     }
00244     tmp_pts      = 0;
00245     tmp_mul      = 1;
00246     tmp_stream   = 0;
00247     tmp_head_idx = 0;
00248     for (i = 0; i < 256;) {
00249         int tmp_flags  = ffio_read_varlen(bc);
00250         int tmp_fields = ffio_read_varlen(bc);
00251 
00252         if (tmp_fields > 0)
00253             tmp_pts = get_s(bc);
00254         if (tmp_fields > 1)
00255             tmp_mul = ffio_read_varlen(bc);
00256         if (tmp_fields > 2)
00257             tmp_stream = ffio_read_varlen(bc);
00258         if (tmp_fields > 3)
00259             tmp_size = ffio_read_varlen(bc);
00260         else
00261             tmp_size = 0;
00262         if (tmp_fields > 4)
00263             tmp_res = ffio_read_varlen(bc);
00264         else
00265             tmp_res = 0;
00266         if (tmp_fields > 5)
00267             count = ffio_read_varlen(bc);
00268         else
00269             count = tmp_mul - tmp_size;
00270         if (tmp_fields > 6)
00271             get_s(bc);
00272         if (tmp_fields > 7)
00273             tmp_head_idx = ffio_read_varlen(bc);
00274 
00275         while (tmp_fields-- > 8)
00276             ffio_read_varlen(bc);
00277 
00278         if (count == 0 || i + count > 256) {
00279             av_log(s, AV_LOG_ERROR, "illegal count %d at %d\n", count, i);
00280             return AVERROR_INVALIDDATA;
00281         }
00282         if (tmp_stream >= stream_count) {
00283             av_log(s, AV_LOG_ERROR, "illegal stream number\n");
00284             return AVERROR_INVALIDDATA;
00285         }
00286 
00287         for (j = 0; j < count; j++, i++) {
00288             if (i == 'N') {
00289                 nut->frame_code[i].flags = FLAG_INVALID;
00290                 j--;
00291                 continue;
00292             }
00293             nut->frame_code[i].flags          = tmp_flags;
00294             nut->frame_code[i].pts_delta      = tmp_pts;
00295             nut->frame_code[i].stream_id      = tmp_stream;
00296             nut->frame_code[i].size_mul       = tmp_mul;
00297             nut->frame_code[i].size_lsb       = tmp_size + j;
00298             nut->frame_code[i].reserved_count = tmp_res;
00299             nut->frame_code[i].header_idx     = tmp_head_idx;
00300         }
00301     }
00302     av_assert0(nut->frame_code['N'].flags == FLAG_INVALID);
00303 
00304     if (end > avio_tell(bc) + 4) {
00305         int rem = 1024;
00306         GET_V(nut->header_count, tmp < 128U)
00307         nut->header_count++;
00308         for (i = 1; i < nut->header_count; i++) {
00309             uint8_t *hdr;
00310             GET_V(nut->header_len[i], tmp > 0 && tmp < 256);
00311             rem -= nut->header_len[i];
00312             if (rem < 0) {
00313                 av_log(s, AV_LOG_ERROR, "invalid elision header\n");
00314                 return AVERROR_INVALIDDATA;
00315             }
00316             hdr = av_malloc(nut->header_len[i]);
00317             if (!hdr)
00318                 return AVERROR(ENOMEM);
00319             avio_read(bc, hdr, nut->header_len[i]);
00320             nut->header[i] = hdr;
00321         }
00322         av_assert0(nut->header_len[0] == 0);
00323     }
00324 
00325     if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {
00326         av_log(s, AV_LOG_ERROR, "main header checksum mismatch\n");
00327         return AVERROR_INVALIDDATA;
00328     }
00329 
00330     nut->stream = av_mallocz(sizeof(StreamContext) * stream_count);
00331     for (i = 0; i < stream_count; i++)
00332         avformat_new_stream(s, NULL);
00333 
00334     return 0;
00335 }
00336 
00337 static int decode_stream_header(NUTContext *nut)
00338 {
00339     AVFormatContext *s = nut->avf;
00340     AVIOContext *bc    = s->pb;
00341     StreamContext *stc;
00342     int class, stream_id;
00343     uint64_t tmp, end;
00344     AVStream *st;
00345 
00346     end  = get_packetheader(nut, bc, 1, STREAM_STARTCODE);
00347     end += avio_tell(bc);
00348 
00349     GET_V(stream_id, tmp < s->nb_streams && !nut->stream[tmp].time_base);
00350     stc = &nut->stream[stream_id];
00351     st  = s->streams[stream_id];
00352     if (!st)
00353         return AVERROR(ENOMEM);
00354 
00355     class                = ffio_read_varlen(bc);
00356     tmp                  = get_fourcc(bc);
00357     st->codec->codec_tag = tmp;
00358     switch (class) {
00359     case 0:
00360         st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00361         st->codec->codec_id   = av_codec_get_id((const AVCodecTag * const []) {
00362                                                     ff_codec_bmp_tags,
00363                                                     ff_nut_video_tags,
00364                                                     0
00365                                                 },
00366                                                 tmp);
00367         break;
00368     case 1:
00369         st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00370         st->codec->codec_id   = ff_codec_get_id(ff_codec_wav_tags, tmp);
00371         break;
00372     case 2:
00373         st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
00374         st->codec->codec_id   = ff_codec_get_id(ff_nut_subtitle_tags, tmp);
00375         break;
00376     case 3:
00377         st->codec->codec_type = AVMEDIA_TYPE_DATA;
00378         break;
00379     default:
00380         av_log(s, AV_LOG_ERROR, "unknown stream class (%d)\n", class);
00381         return -1;
00382     }
00383     if (class < 3 && st->codec->codec_id == AV_CODEC_ID_NONE)
00384         av_log(s, AV_LOG_ERROR,
00385                "Unknown codec tag '0x%04x' for stream number %d\n",
00386                (unsigned int) tmp, stream_id);
00387 
00388     GET_V(stc->time_base_id, tmp < nut->time_base_count);
00389     GET_V(stc->msb_pts_shift, tmp < 16);
00390     stc->max_pts_distance = ffio_read_varlen(bc);
00391     GET_V(stc->decode_delay, tmp < 1000); // sanity limit, raise this if Moore's law is true
00392     st->codec->has_b_frames = stc->decode_delay;
00393     ffio_read_varlen(bc); // stream flags
00394 
00395     GET_V(st->codec->extradata_size, tmp < (1 << 30));
00396     if (st->codec->extradata_size) {
00397         st->codec->extradata = av_mallocz(st->codec->extradata_size +
00398                                           FF_INPUT_BUFFER_PADDING_SIZE);
00399         avio_read(bc, st->codec->extradata, st->codec->extradata_size);
00400     }
00401 
00402     if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
00403         GET_V(st->codec->width,  tmp > 0)
00404         GET_V(st->codec->height, tmp > 0)
00405         st->sample_aspect_ratio.num = ffio_read_varlen(bc);
00406         st->sample_aspect_ratio.den = ffio_read_varlen(bc);
00407         if ((!st->sample_aspect_ratio.num) != (!st->sample_aspect_ratio.den)) {
00408             av_log(s, AV_LOG_ERROR, "invalid aspect ratio %d/%d\n",
00409                    st->sample_aspect_ratio.num, st->sample_aspect_ratio.den);
00410             return -1;
00411         }
00412         ffio_read_varlen(bc); /* csp type */
00413     } else if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
00414         GET_V(st->codec->sample_rate, tmp > 0)
00415         ffio_read_varlen(bc); // samplerate_den
00416         GET_V(st->codec->channels, tmp > 0)
00417     }
00418     if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {
00419         av_log(s, AV_LOG_ERROR,
00420                "stream header %d checksum mismatch\n", stream_id);
00421         return -1;
00422     }
00423     stc->time_base = &nut->time_base[stc->time_base_id];
00424     avpriv_set_pts_info(s->streams[stream_id], 63, stc->time_base->num,
00425                         stc->time_base->den);
00426     return 0;
00427 }
00428 
00429 static void set_disposition_bits(AVFormatContext *avf, char *value,
00430                                  int stream_id)
00431 {
00432     int flag = 0, i;
00433 
00434     for (i = 0; ff_nut_dispositions[i].flag; ++i)
00435         if (!strcmp(ff_nut_dispositions[i].str, value))
00436             flag = ff_nut_dispositions[i].flag;
00437     if (!flag)
00438         av_log(avf, AV_LOG_INFO, "unknown disposition type '%s'\n", value);
00439     for (i = 0; i < avf->nb_streams; ++i)
00440         if (stream_id == i || stream_id == -1)
00441             avf->streams[i]->disposition |= flag;
00442 }
00443 
00444 static int decode_info_header(NUTContext *nut)
00445 {
00446     AVFormatContext *s = nut->avf;
00447     AVIOContext *bc    = s->pb;
00448     uint64_t tmp, chapter_start, chapter_len;
00449     unsigned int stream_id_plus1, count;
00450     int chapter_id, i;
00451     int64_t value, end;
00452     char name[256], str_value[1024], type_str[256];
00453     const char *type;
00454     AVChapter *chapter      = NULL;
00455     AVStream *st            = NULL;
00456     AVDictionary **metadata = NULL;
00457 
00458     end  = get_packetheader(nut, bc, 1, INFO_STARTCODE);
00459     end += avio_tell(bc);
00460 
00461     GET_V(stream_id_plus1, tmp <= s->nb_streams)
00462     chapter_id    = get_s(bc);
00463     chapter_start = ffio_read_varlen(bc);
00464     chapter_len   = ffio_read_varlen(bc);
00465     count         = ffio_read_varlen(bc);
00466 
00467     if (chapter_id && !stream_id_plus1) {
00468         int64_t start = chapter_start / nut->time_base_count;
00469         chapter = avpriv_new_chapter(s, chapter_id,
00470                                      nut->time_base[chapter_start %
00471                                                     nut->time_base_count],
00472                                      start, start + chapter_len, NULL);
00473         metadata = &chapter->metadata;
00474     } else if (stream_id_plus1) {
00475         st       = s->streams[stream_id_plus1 - 1];
00476         metadata = &st->metadata;
00477     } else
00478         metadata = &s->metadata;
00479 
00480     for (i = 0; i < count; i++) {
00481         get_str(bc, name, sizeof(name));
00482         value = get_s(bc);
00483         if (value == -1) {
00484             type = "UTF-8";
00485             get_str(bc, str_value, sizeof(str_value));
00486         } else if (value == -2) {
00487             get_str(bc, type_str, sizeof(type_str));
00488             type = type_str;
00489             get_str(bc, str_value, sizeof(str_value));
00490         } else if (value == -3) {
00491             type  = "s";
00492             value = get_s(bc);
00493         } else if (value == -4) {
00494             type  = "t";
00495             value = ffio_read_varlen(bc);
00496         } else if (value < -4) {
00497             type = "r";
00498             get_s(bc);
00499         } else {
00500             type = "v";
00501         }
00502 
00503         if (stream_id_plus1 > s->nb_streams) {
00504             av_log(s, AV_LOG_ERROR, "invalid stream id for info packet\n");
00505             continue;
00506         }
00507 
00508         if (!strcmp(type, "UTF-8")) {
00509             if (chapter_id == 0 && !strcmp(name, "Disposition")) {
00510                 set_disposition_bits(s, str_value, stream_id_plus1 - 1);
00511                 continue;
00512             }
00513             if (metadata && av_strcasecmp(name, "Uses") &&
00514                 av_strcasecmp(name, "Depends") && av_strcasecmp(name, "Replaces"))
00515                 av_dict_set(metadata, name, str_value, 0);
00516         }
00517     }
00518 
00519     if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {
00520         av_log(s, AV_LOG_ERROR, "info header checksum mismatch\n");
00521         return -1;
00522     }
00523     return 0;
00524 }
00525 
00526 static int decode_syncpoint(NUTContext *nut, int64_t *ts, int64_t *back_ptr)
00527 {
00528     AVFormatContext *s = nut->avf;
00529     AVIOContext *bc    = s->pb;
00530     int64_t end;
00531     uint64_t tmp;
00532 
00533     nut->last_syncpoint_pos = avio_tell(bc) - 8;
00534 
00535     end  = get_packetheader(nut, bc, 1, SYNCPOINT_STARTCODE);
00536     end += avio_tell(bc);
00537 
00538     tmp       = ffio_read_varlen(bc);
00539     *back_ptr = nut->last_syncpoint_pos - 16 * ffio_read_varlen(bc);
00540     if (*back_ptr < 0)
00541         return -1;
00542 
00543     ff_nut_reset_ts(nut, nut->time_base[tmp % nut->time_base_count],
00544                     tmp / nut->time_base_count);
00545 
00546     if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {
00547         av_log(s, AV_LOG_ERROR, "sync point checksum mismatch\n");
00548         return -1;
00549     }
00550 
00551     *ts = tmp / nut->time_base_count *
00552           av_q2d(nut->time_base[tmp % nut->time_base_count]) * AV_TIME_BASE;
00553     ff_nut_add_sp(nut, nut->last_syncpoint_pos, *back_ptr, *ts);
00554 
00555     return 0;
00556 }
00557 
00558 //FIXME calculate exactly, this is just a good approximation.
00559 static int64_t find_duration(NUTContext *nut, int64_t filesize)
00560 {
00561     AVFormatContext *s = nut->avf;
00562     int64_t duration = 0;
00563 
00564     int64_t pos = FFMAX(0, filesize - 2*nut->max_distance);
00565     for(;;){
00566         int64_t ts = nut_read_timestamp(s, -1, &pos, INT64_MAX);
00567         if(ts < 0)
00568             break;
00569         duration = FFMAX(duration, ts);
00570         pos++;
00571     }
00572     if(duration > 0)
00573         s->duration_estimation_method = AVFMT_DURATION_FROM_PTS;
00574     return duration;
00575 }
00576 
00577 static int find_and_decode_index(NUTContext *nut)
00578 {
00579     AVFormatContext *s = nut->avf;
00580     AVIOContext *bc    = s->pb;
00581     uint64_t tmp, end;
00582     int i, j, syncpoint_count;
00583     int64_t filesize = avio_size(bc);
00584     int64_t *syncpoints;
00585     int8_t *has_keyframe;
00586     int ret = -1;
00587 
00588     if(filesize <= 0)
00589         return -1;
00590 
00591     avio_seek(bc, filesize - 12, SEEK_SET);
00592     avio_seek(bc, filesize - avio_rb64(bc), SEEK_SET);
00593     if (avio_rb64(bc) != INDEX_STARTCODE) {
00594         av_log(s, AV_LOG_ERROR, "no index at the end\n");
00595 
00596         if(s->duration<=0)
00597             s->duration = find_duration(nut, filesize);
00598         return -1;
00599     }
00600 
00601     end  = get_packetheader(nut, bc, 1, INDEX_STARTCODE);
00602     end += avio_tell(bc);
00603 
00604     ffio_read_varlen(bc); // max_pts
00605     GET_V(syncpoint_count, tmp < INT_MAX / 8 && tmp > 0)
00606     syncpoints   = av_malloc(sizeof(int64_t) *  syncpoint_count);
00607     has_keyframe = av_malloc(sizeof(int8_t)  * (syncpoint_count + 1));
00608     for (i = 0; i < syncpoint_count; i++) {
00609         syncpoints[i] = ffio_read_varlen(bc);
00610         if (syncpoints[i] <= 0)
00611             goto fail;
00612         if (i)
00613             syncpoints[i] += syncpoints[i - 1];
00614     }
00615 
00616     for (i = 0; i < s->nb_streams; i++) {
00617         int64_t last_pts = -1;
00618         for (j = 0; j < syncpoint_count;) {
00619             uint64_t x = ffio_read_varlen(bc);
00620             int type   = x & 1;
00621             int n      = j;
00622             x >>= 1;
00623             if (type) {
00624                 int flag = x & 1;
00625                 x >>= 1;
00626                 if (n + x >= syncpoint_count + 1) {
00627                     av_log(s, AV_LOG_ERROR, "index overflow A %d + %"PRIu64" >= %d\n", n, x, syncpoint_count + 1);
00628                     goto fail;
00629                 }
00630                 while (x--)
00631                     has_keyframe[n++] = flag;
00632                 has_keyframe[n++] = !flag;
00633             } else {
00634                 while (x != 1) {
00635                     if (n >= syncpoint_count + 1) {
00636                         av_log(s, AV_LOG_ERROR, "index overflow B\n");
00637                         goto fail;
00638                     }
00639                     has_keyframe[n++] = x & 1;
00640                     x >>= 1;
00641                 }
00642             }
00643             if (has_keyframe[0]) {
00644                 av_log(s, AV_LOG_ERROR, "keyframe before first syncpoint in index\n");
00645                 goto fail;
00646             }
00647             av_assert0(n <= syncpoint_count + 1);
00648             for (; j < n && j < syncpoint_count; j++) {
00649                 if (has_keyframe[j]) {
00650                     uint64_t B, A = ffio_read_varlen(bc);
00651                     if (!A) {
00652                         A = ffio_read_varlen(bc);
00653                         B = ffio_read_varlen(bc);
00654                         // eor_pts[j][i] = last_pts + A + B
00655                     } else
00656                         B = 0;
00657                     av_add_index_entry(s->streams[i], 16 * syncpoints[j - 1],
00658                                        last_pts + A, 0, 0, AVINDEX_KEYFRAME);
00659                     last_pts += A + B;
00660                 }
00661             }
00662         }
00663     }
00664 
00665     if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {
00666         av_log(s, AV_LOG_ERROR, "index checksum mismatch\n");
00667         goto fail;
00668     }
00669     ret = 0;
00670 
00671 fail:
00672     av_free(syncpoints);
00673     av_free(has_keyframe);
00674     return ret;
00675 }
00676 
00677 static int nut_read_header(AVFormatContext *s)
00678 {
00679     NUTContext *nut = s->priv_data;
00680     AVIOContext *bc = s->pb;
00681     int64_t pos;
00682     int initialized_stream_count;
00683 
00684     nut->avf = s;
00685 
00686     /* main header */
00687     pos = 0;
00688     do {
00689         pos = find_startcode(bc, MAIN_STARTCODE, pos) + 1;
00690         if (pos < 0 + 1) {
00691             av_log(s, AV_LOG_ERROR, "No main startcode found.\n");
00692             return AVERROR_INVALIDDATA;
00693         }
00694     } while (decode_main_header(nut) < 0);
00695 
00696     /* stream headers */
00697     pos = 0;
00698     for (initialized_stream_count = 0; initialized_stream_count < s->nb_streams;) {
00699         pos = find_startcode(bc, STREAM_STARTCODE, pos) + 1;
00700         if (pos < 0 + 1) {
00701             av_log(s, AV_LOG_ERROR, "Not all stream headers found.\n");
00702             return AVERROR_INVALIDDATA;
00703         }
00704         if (decode_stream_header(nut) >= 0)
00705             initialized_stream_count++;
00706     }
00707 
00708     /* info headers */
00709     pos = 0;
00710     for (;;) {
00711         uint64_t startcode = find_any_startcode(bc, pos);
00712         pos = avio_tell(bc);
00713 
00714         if (startcode == 0) {
00715             av_log(s, AV_LOG_ERROR, "EOF before video frames\n");
00716             return AVERROR_INVALIDDATA;
00717         } else if (startcode == SYNCPOINT_STARTCODE) {
00718             nut->next_startcode = startcode;
00719             break;
00720         } else if (startcode != INFO_STARTCODE) {
00721             continue;
00722         }
00723 
00724         decode_info_header(nut);
00725     }
00726 
00727     s->data_offset = pos - 8;
00728 
00729     if (bc->seekable) {
00730         int64_t orig_pos = avio_tell(bc);
00731         find_and_decode_index(nut);
00732         avio_seek(bc, orig_pos, SEEK_SET);
00733     }
00734     av_assert0(nut->next_startcode == SYNCPOINT_STARTCODE);
00735 
00736     ff_metadata_conv_ctx(s, NULL, ff_nut_metadata_conv);
00737 
00738     return 0;
00739 }
00740 
00741 static int decode_frame_header(NUTContext *nut, int64_t *pts, int *stream_id,
00742                                uint8_t *header_idx, int frame_code)
00743 {
00744     AVFormatContext *s = nut->avf;
00745     AVIOContext *bc    = s->pb;
00746     StreamContext *stc;
00747     int size, flags, size_mul, pts_delta, i, reserved_count;
00748     uint64_t tmp;
00749 
00750     if (avio_tell(bc) > nut->last_syncpoint_pos + nut->max_distance) {
00751         av_log(s, AV_LOG_ERROR,
00752                "Last frame must have been damaged %"PRId64" > %"PRId64" + %d\n",
00753                avio_tell(bc), nut->last_syncpoint_pos, nut->max_distance);
00754         return AVERROR_INVALIDDATA;
00755     }
00756 
00757     flags          = nut->frame_code[frame_code].flags;
00758     size_mul       = nut->frame_code[frame_code].size_mul;
00759     size           = nut->frame_code[frame_code].size_lsb;
00760     *stream_id     = nut->frame_code[frame_code].stream_id;
00761     pts_delta      = nut->frame_code[frame_code].pts_delta;
00762     reserved_count = nut->frame_code[frame_code].reserved_count;
00763     *header_idx    = nut->frame_code[frame_code].header_idx;
00764 
00765     if (flags & FLAG_INVALID)
00766         return AVERROR_INVALIDDATA;
00767     if (flags & FLAG_CODED)
00768         flags ^= ffio_read_varlen(bc);
00769     if (flags & FLAG_STREAM_ID) {
00770         GET_V(*stream_id, tmp < s->nb_streams)
00771     }
00772     stc = &nut->stream[*stream_id];
00773     if (flags & FLAG_CODED_PTS) {
00774         int coded_pts = ffio_read_varlen(bc);
00775         // FIXME check last_pts validity?
00776         if (coded_pts < (1 << stc->msb_pts_shift)) {
00777             *pts = ff_lsb2full(stc, coded_pts);
00778         } else
00779             *pts = coded_pts - (1 << stc->msb_pts_shift);
00780     } else
00781         *pts = stc->last_pts + pts_delta;
00782     if (flags & FLAG_SIZE_MSB)
00783         size += size_mul * ffio_read_varlen(bc);
00784     if (flags & FLAG_MATCH_TIME)
00785         get_s(bc);
00786     if (flags & FLAG_HEADER_IDX)
00787         *header_idx = ffio_read_varlen(bc);
00788     if (flags & FLAG_RESERVED)
00789         reserved_count = ffio_read_varlen(bc);
00790     for (i = 0; i < reserved_count; i++)
00791         ffio_read_varlen(bc);
00792 
00793     if (*header_idx >= (unsigned)nut->header_count) {
00794         av_log(s, AV_LOG_ERROR, "header_idx invalid\n");
00795         return AVERROR_INVALIDDATA;
00796     }
00797     if (size > 4096)
00798         *header_idx = 0;
00799     size -= nut->header_len[*header_idx];
00800 
00801     if (flags & FLAG_CHECKSUM) {
00802         avio_rb32(bc); // FIXME check this
00803     } else if (size > 2 * nut->max_distance || FFABS(stc->last_pts - *pts) >
00804                stc->max_pts_distance) {
00805         av_log(s, AV_LOG_ERROR, "frame size > 2max_distance and no checksum\n");
00806         return AVERROR_INVALIDDATA;
00807     }
00808 
00809     stc->last_pts   = *pts;
00810     stc->last_flags = flags;
00811 
00812     return size;
00813 }
00814 
00815 static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code)
00816 {
00817     AVFormatContext *s = nut->avf;
00818     AVIOContext *bc    = s->pb;
00819     int size, stream_id, discard;
00820     int64_t pts, last_IP_pts;
00821     StreamContext *stc;
00822     uint8_t header_idx;
00823 
00824     size = decode_frame_header(nut, &pts, &stream_id, &header_idx, frame_code);
00825     if (size < 0)
00826         return size;
00827 
00828     stc = &nut->stream[stream_id];
00829 
00830     if (stc->last_flags & FLAG_KEY)
00831         stc->skip_until_key_frame = 0;
00832 
00833     discard     = s->streams[stream_id]->discard;
00834     last_IP_pts = s->streams[stream_id]->last_IP_pts;
00835     if ((discard >= AVDISCARD_NONKEY && !(stc->last_flags & FLAG_KEY)) ||
00836         (discard >= AVDISCARD_BIDIR  && last_IP_pts != AV_NOPTS_VALUE &&
00837          last_IP_pts > pts) ||
00838         discard >= AVDISCARD_ALL ||
00839         stc->skip_until_key_frame) {
00840         avio_skip(bc, size);
00841         return 1;
00842     }
00843 
00844     av_new_packet(pkt, size + nut->header_len[header_idx]);
00845     memcpy(pkt->data, nut->header[header_idx], nut->header_len[header_idx]);
00846     pkt->pos = avio_tell(bc); // FIXME
00847     avio_read(bc, pkt->data + nut->header_len[header_idx], size);
00848 
00849     pkt->stream_index = stream_id;
00850     if (stc->last_flags & FLAG_KEY)
00851         pkt->flags |= AV_PKT_FLAG_KEY;
00852     pkt->pts = pts;
00853 
00854     return 0;
00855 }
00856 
00857 static int nut_read_packet(AVFormatContext *s, AVPacket *pkt)
00858 {
00859     NUTContext *nut = s->priv_data;
00860     AVIOContext *bc = s->pb;
00861     int i, frame_code = 0, ret, skip;
00862     int64_t ts, back_ptr;
00863 
00864     for (;;) {
00865         int64_t pos  = avio_tell(bc);
00866         uint64_t tmp = nut->next_startcode;
00867         nut->next_startcode = 0;
00868 
00869         if (tmp) {
00870             pos -= 8;
00871         } else {
00872             frame_code = avio_r8(bc);
00873             if (url_feof(bc))
00874                 return -1;
00875             if (frame_code == 'N') {
00876                 tmp = frame_code;
00877                 for (i = 1; i < 8; i++)
00878                     tmp = (tmp << 8) + avio_r8(bc);
00879             }
00880         }
00881         switch (tmp) {
00882         case MAIN_STARTCODE:
00883         case STREAM_STARTCODE:
00884         case INDEX_STARTCODE:
00885             skip = get_packetheader(nut, bc, 0, tmp);
00886             avio_skip(bc, skip);
00887             break;
00888         case INFO_STARTCODE:
00889             if (decode_info_header(nut) < 0)
00890                 goto resync;
00891             break;
00892         case SYNCPOINT_STARTCODE:
00893             if (decode_syncpoint(nut, &ts, &back_ptr) < 0)
00894                 goto resync;
00895             frame_code = avio_r8(bc);
00896         case 0:
00897             ret = decode_frame(nut, pkt, frame_code);
00898             if (ret == 0)
00899                 return 0;
00900             else if (ret == 1) // OK but discard packet
00901                 break;
00902         default:
00903 resync:
00904             av_log(s, AV_LOG_DEBUG, "syncing from %"PRId64"\n", pos);
00905             tmp = find_any_startcode(bc, nut->last_syncpoint_pos + 1);
00906             if (tmp == 0)
00907                 return AVERROR_INVALIDDATA;
00908             av_log(s, AV_LOG_DEBUG, "sync\n");
00909             nut->next_startcode = tmp;
00910         }
00911     }
00912 }
00913 
00914 static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index,
00915                                   int64_t *pos_arg, int64_t pos_limit)
00916 {
00917     NUTContext *nut = s->priv_data;
00918     AVIOContext *bc = s->pb;
00919     int64_t pos, pts, back_ptr;
00920     av_log(s, AV_LOG_DEBUG, "read_timestamp(X,%d,%"PRId64",%"PRId64")\n",
00921            stream_index, *pos_arg, pos_limit);
00922 
00923     pos = *pos_arg;
00924     do {
00925         pos = find_startcode(bc, SYNCPOINT_STARTCODE, pos) + 1;
00926         if (pos < 1) {
00927             av_log(s, AV_LOG_ERROR, "read_timestamp failed.\n");
00928             return AV_NOPTS_VALUE;
00929         }
00930     } while (decode_syncpoint(nut, &pts, &back_ptr) < 0);
00931     *pos_arg = pos - 1;
00932     av_assert0(nut->last_syncpoint_pos == *pos_arg);
00933 
00934     av_log(s, AV_LOG_DEBUG, "return %"PRId64" %"PRId64"\n", pts, back_ptr);
00935     if (stream_index == -2)
00936         return back_ptr;
00937     av_assert0(stream_index == -1);
00938     return pts;
00939 }
00940 
00941 static int read_seek(AVFormatContext *s, int stream_index,
00942                      int64_t pts, int flags)
00943 {
00944     NUTContext *nut    = s->priv_data;
00945     AVStream *st       = s->streams[stream_index];
00946     Syncpoint dummy    = { .ts = pts * av_q2d(st->time_base) * AV_TIME_BASE };
00947     Syncpoint nopts_sp = { .ts = AV_NOPTS_VALUE, .back_ptr = AV_NOPTS_VALUE };
00948     Syncpoint *sp, *next_node[2] = { &nopts_sp, &nopts_sp };
00949     int64_t pos, pos2, ts;
00950     int i;
00951 
00952     if (st->index_entries) {
00953         int index = av_index_search_timestamp(st, pts, flags);
00954         if (index < 0)
00955             index = av_index_search_timestamp(st, pts, flags ^ AVSEEK_FLAG_BACKWARD);
00956         if (index < 0)
00957             return -1;
00958 
00959         pos2 = st->index_entries[index].pos;
00960         ts   = st->index_entries[index].timestamp;
00961     } else {
00962         av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pts_cmp,
00963                      (void **) next_node);
00964         av_log(s, AV_LOG_DEBUG, "%"PRIu64"-%"PRIu64" %"PRId64"-%"PRId64"\n",
00965                next_node[0]->pos, next_node[1]->pos, next_node[0]->ts,
00966                next_node[1]->ts);
00967         pos = ff_gen_search(s, -1, dummy.ts, next_node[0]->pos,
00968                             next_node[1]->pos, next_node[1]->pos,
00969                             next_node[0]->ts, next_node[1]->ts,
00970                             AVSEEK_FLAG_BACKWARD, &ts, nut_read_timestamp);
00971 
00972         if (!(flags & AVSEEK_FLAG_BACKWARD)) {
00973             dummy.pos    = pos + 16;
00974             next_node[1] = &nopts_sp;
00975             av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pos_cmp,
00976                          (void **) next_node);
00977             pos2 = ff_gen_search(s, -2, dummy.pos, next_node[0]->pos,
00978                                  next_node[1]->pos, next_node[1]->pos,
00979                                  next_node[0]->back_ptr, next_node[1]->back_ptr,
00980                                  flags, &ts, nut_read_timestamp);
00981             if (pos2 >= 0)
00982                 pos = pos2;
00983             // FIXME dir but I think it does not matter
00984         }
00985         dummy.pos = pos;
00986         sp = av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pos_cmp,
00987                           NULL);
00988 
00989         av_assert0(sp);
00990         pos2 = sp->back_ptr - 15;
00991     }
00992     av_log(NULL, AV_LOG_DEBUG, "SEEKTO: %"PRId64"\n", pos2);
00993     pos = find_startcode(s->pb, SYNCPOINT_STARTCODE, pos2);
00994     avio_seek(s->pb, pos, SEEK_SET);
00995     av_log(NULL, AV_LOG_DEBUG, "SP: %"PRId64"\n", pos);
00996     if (pos2 > pos || pos2 + 15 < pos)
00997         av_log(NULL, AV_LOG_ERROR, "no syncpoint at backptr pos\n");
00998     for (i = 0; i < s->nb_streams; i++)
00999         nut->stream[i].skip_until_key_frame = 1;
01000 
01001     return 0;
01002 }
01003 
01004 static int nut_read_close(AVFormatContext *s)
01005 {
01006     NUTContext *nut = s->priv_data;
01007     int i;
01008 
01009     av_freep(&nut->time_base);
01010     av_freep(&nut->stream);
01011     ff_nut_free_sp(nut);
01012     for (i = 1; i < nut->header_count; i++)
01013         av_freep(&nut->header[i]);
01014 
01015     return 0;
01016 }
01017 
01018 AVInputFormat ff_nut_demuxer = {
01019     .name           = "nut",
01020     .long_name      = NULL_IF_CONFIG_SMALL("NUT"),
01021     .flags          = AVFMT_SEEK_TO_PTS,
01022     .priv_data_size = sizeof(NUTContext),
01023     .read_probe     = nut_probe,
01024     .read_header    = nut_read_header,
01025     .read_packet    = nut_read_packet,
01026     .read_close     = nut_read_close,
01027     .read_seek      = read_seek,
01028     .extensions     = "nut",
01029     .codec_tag      = (const AVCodecTag * const []) {
01030         ff_codec_bmp_tags, ff_nut_video_tags, ff_codec_wav_tags,
01031         ff_nut_subtitle_tags, 0
01032     },
01033 };