static AVIOContext * wtvfile_open_sector(int first_sector, uint64_t length, int depth, AVFormatContext *s) { AVIOContext *pb; WtvFile *wf; uint8_t *buffer; if (avio_seek(s->pb, (int64_t)first_sector << WTV_SECTOR_BITS, SEEK_SET) < 0) return NULL; wf = av_mallocz(sizeof(WtvFile)); if (!wf) return NULL; if (depth == 0) { wf->sectors = av_malloc(sizeof(uint32_t)); if (!wf->sectors) { av_free(wf); return NULL; } wf->sectors[0] = first_sector; wf->nb_sectors = 1; } else if (depth == 1) { wf->sectors = av_malloc(WTV_SECTOR_SIZE); if (!wf->sectors) { av_free(wf); return NULL; } wf->nb_sectors = read_ints(s->pb, wf->sectors, WTV_SECTOR_SIZE / 4); } else if (depth == 2) { uint32_t sectors1[WTV_SECTOR_SIZE / 4]; int nb_sectors1 = read_ints(s->pb, sectors1, WTV_SECTOR_SIZE / 4); int i; wf->sectors = av_malloc(nb_sectors1 << WTV_SECTOR_BITS); if (!wf->sectors) { av_free(wf); return NULL; } wf->nb_sectors = 0; for (i = 0; i < nb_sectors1; i++) { if (avio_seek(s->pb, (int64_t)sectors1[i] << WTV_SECTOR_BITS, SEEK_SET) < 0) break; wf->nb_sectors += read_ints(s->pb, wf->sectors + i * WTV_SECTOR_SIZE / 4, WTV_SECTOR_SIZE / 4); } } else { av_log(s, AV_LOG_ERROR, "unsupported file allocation table depth (0x%x)\n", depth); av_free(wf); return NULL; } wf->sector_bits = length & (1ULL<<63) ? WTV_SECTOR_BITS : WTV_BIGSECTOR_BITS; if (!wf->nb_sectors) { av_free(wf->sectors); av_free(wf); return NULL; } if (wf->sectors[wf->nb_sectors - 1] << WTV_SECTOR_BITS > avio_tell(s->pb)) av_log(s, AV_LOG_WARNING, "truncated file\n"); /* check length */ length &= 0xFFFFFFFFFFFF; if (length > ((int64_t)wf->nb_sectors << wf->sector_bits)) { av_log(s, AV_LOG_WARNING, "reported file length (0x%"PRIx64") exceeds number of available sectors (0x%"PRIx64")\n", length, (int64_t)wf->nb_sectors << wf->sector_bits); length = (int64_t)wf->nb_sectors << wf->sector_bits; } wf->length = length; /* seek to initial sector */ wf->position = 0; if (avio_seek(s->pb, (int64_t)wf->sectors[0] << WTV_SECTOR_BITS, SEEK_SET) < 0) { av_free(wf->sectors); av_free(wf); return NULL; } wf->pb_filesystem = s->pb; buffer = av_malloc(1 << wf->sector_bits); if (!buffer) { av_free(wf->sectors); av_free(wf); return NULL; } pb = avio_alloc_context(buffer, 1 << wf->sector_bits, 0, wf, wtvfile_read_packet, NULL, wtvfile_seek); if (!pb) { av_free(buffer); av_free(wf->sectors); av_free(wf); } return pb; }