X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavformat%2Faadec.c;h=d83f283ffe3b3a50491b0b32c9cd84cf281180e9;hb=762c2b5dcd99a08452299cd1f83070f88115f1f3;hp=8d39b1d9baa048c0084b7879043951026add2ce5;hpb=9e3e9a37289c1a9cdfdb6c7389a3ece3cfa4749c;p=ffmpeg diff --git a/libavformat/aadec.c b/libavformat/aadec.c index 8d39b1d9baa..d83f283ffe3 100644 --- a/libavformat/aadec.c +++ b/libavformat/aadec.c @@ -35,6 +35,9 @@ #define MAX_TOC_ENTRIES 16 #define MAX_DICTIONARY_ENTRIES 128 #define TEA_BLOCK_SIZE 8 +#define CHAPTER_HEADER_SIZE 8 +#define TIMEPREC 1000 +#define MP3_FRAME_SIZE 104 typedef struct AADemuxContext { AVClass *class; @@ -46,6 +49,9 @@ typedef struct AADemuxContext { struct AVTEA *tea_ctx; uint8_t file_key[16]; int64_t current_chapter_size; + int64_t content_start; + int64_t content_end; + int seek_offset; } AADemuxContext; static int get_second_size(char *codec_name) @@ -69,7 +75,7 @@ static int aa_read_header(AVFormatContext *s) uint32_t nkey, nval, toc_size, npairs, header_seed = 0, start; char key[128], val[128], codec_name[64] = {0}; uint8_t output[24], dst[8], src[8]; - int64_t largest_size = -1, current_size = -1; + int64_t largest_size = -1, current_size = -1, chapter_pos; struct toc_entry { uint32_t offset; uint32_t size; @@ -172,19 +178,24 @@ static int aa_read_header(AVFormatContext *s) st->codecpar->codec_id = AV_CODEC_ID_MP3; st->codecpar->sample_rate = 22050; st->need_parsing = AVSTREAM_PARSE_FULL_RAW; - st->start_time = 0; + avpriv_set_pts_info(st, 64, 8, 32000 * TIMEPREC); + // encoded audio frame is MP3_FRAME_SIZE bytes (+1 with padding, unlikely) } else if (!strcmp(codec_name, "acelp85")) { st->codecpar->codec_id = AV_CODEC_ID_SIPR; st->codecpar->block_align = 19; st->codecpar->channels = 1; st->codecpar->sample_rate = 8500; + st->codecpar->bit_rate = 8500; st->need_parsing = AVSTREAM_PARSE_FULL_RAW; + avpriv_set_pts_info(st, 64, 8, 8500 * TIMEPREC); } else if (!strcmp(codec_name, "acelp16")) { st->codecpar->codec_id = AV_CODEC_ID_SIPR; st->codecpar->block_align = 20; st->codecpar->channels = 1; st->codecpar->sample_rate = 16000; + st->codecpar->bit_rate = 16000; st->need_parsing = AVSTREAM_PARSE_FULL_RAW; + avpriv_set_pts_info(st, 64, 8, 16000 * TIMEPREC); } /* determine, and jump to audio start offset */ @@ -197,7 +208,30 @@ static int aa_read_header(AVFormatContext *s) } start = TOC[largest_idx].offset; avio_seek(pb, start, SEEK_SET); + + // extract chapter positions. since all formats have constant bit rate, use it + // as time base in bytes/s, for easy stream position <-> timestamp conversion + st->start_time = 0; + c->content_start = start; + c->content_end = start + largest_size; + + while ((chapter_pos = avio_tell(pb)) >= 0 && chapter_pos < c->content_end) { + int chapter_idx = s->nb_chapters; + uint32_t chapter_size = avio_rb32(pb); + if (chapter_size == 0) break; + chapter_pos -= start + CHAPTER_HEADER_SIZE * chapter_idx; + avio_skip(pb, 4 + chapter_size); + if (!avpriv_new_chapter(s, chapter_idx, st->time_base, + chapter_pos * TIMEPREC, (chapter_pos + chapter_size) * TIMEPREC, NULL)) + return AVERROR(ENOMEM); + } + + st->duration = (largest_size - CHAPTER_HEADER_SIZE * s->nb_chapters) * TIMEPREC; + + ff_update_cur_dts(s, st, 0); + avio_seek(pb, start, SEEK_SET); c->current_chapter_size = 0; + c->seek_offset = 0; return 0; } @@ -213,6 +247,12 @@ static int aa_read_packet(AVFormatContext *s, AVPacket *pkt) int written = 0; int ret; AADemuxContext *c = s->priv_data; + uint64_t pos = avio_tell(s->pb); + + // are we at the end of the audio content? + if (pos >= c->content_end) { + return AVERROR_EOF; + } // are we at the start of a chapter? if (c->current_chapter_size == 0) { @@ -223,6 +263,7 @@ static int aa_read_packet(AVFormatContext *s, AVPacket *pkt) av_log(s, AV_LOG_DEBUG, "Chapter %d (%" PRId64 " bytes)\n", c->chapter_idx, c->current_chapter_size); c->chapter_idx = c->chapter_idx + 1; avio_skip(s->pb, 4); // data start offset + pos += 8; c->current_codec_second_size = c->codec_second_size; } @@ -234,7 +275,9 @@ static int aa_read_packet(AVFormatContext *s, AVPacket *pkt) // decrypt c->current_codec_second_size bytes blocks = c->current_codec_second_size / TEA_BLOCK_SIZE; for (i = 0; i < blocks; i++) { - avio_read(s->pb, src, TEA_BLOCK_SIZE); + ret = avio_read(s->pb, src, TEA_BLOCK_SIZE); + if (ret != TEA_BLOCK_SIZE) + return (ret < 0) ? ret : AVERROR_EOF; av_tea_init(c->tea_ctx, c->file_key, 16); av_tea_crypt(c->tea_ctx, dst, src, 1, NULL, 1); memcpy(buf + written, dst, TEA_BLOCK_SIZE); @@ -242,7 +285,9 @@ static int aa_read_packet(AVFormatContext *s, AVPacket *pkt) } trailing_bytes = c->current_codec_second_size % TEA_BLOCK_SIZE; if (trailing_bytes != 0) { // trailing bytes are left unencrypted! - avio_read(s->pb, src, trailing_bytes); + ret = avio_read(s->pb, src, trailing_bytes); + if (ret != trailing_bytes) + return (ret < 0) ? ret : AVERROR_EOF; memcpy(buf + written, src, trailing_bytes); written = written + trailing_bytes; } @@ -252,14 +297,69 @@ static int aa_read_packet(AVFormatContext *s, AVPacket *pkt) if (c->current_chapter_size <= 0) c->current_chapter_size = 0; - ret = av_new_packet(pkt, written); + if (c->seek_offset > written) + c->seek_offset = 0; // ignore wrong estimate + + ret = av_new_packet(pkt, written - c->seek_offset); if (ret < 0) return ret; - memcpy(pkt->data, buf, written); + memcpy(pkt->data, buf + c->seek_offset, written - c->seek_offset); + pkt->pos = pos; + c->seek_offset = 0; return 0; } +static int aa_read_seek(AVFormatContext *s, + int stream_index, int64_t timestamp, int flags) +{ + AADemuxContext *c = s->priv_data; + AVChapter *ch; + int64_t chapter_pos, chapter_start, chapter_size; + int chapter_idx = 0; + + // find chapter containing seek timestamp + if (timestamp < 0) + timestamp = 0; + + while (chapter_idx < s->nb_chapters && timestamp >= s->chapters[chapter_idx]->end) { + ++chapter_idx; + } + + if (chapter_idx >= s->nb_chapters) { + chapter_idx = s->nb_chapters - 1; + if (chapter_idx < 0) return -1; // there is no chapter. + timestamp = s->chapters[chapter_idx]->end; + } + + ch = s->chapters[chapter_idx]; + + // sync by clamping timestamp to nearest valid block position in its chapter + chapter_size = ch->end / TIMEPREC - ch->start / TIMEPREC; + chapter_pos = av_rescale_rnd((timestamp - ch->start) / TIMEPREC, + 1, c->codec_second_size, + (flags & AVSEEK_FLAG_BACKWARD) ? AV_ROUND_DOWN : AV_ROUND_UP) + * c->codec_second_size; + if (chapter_pos >= chapter_size) + chapter_pos = chapter_size; + chapter_start = c->content_start + (ch->start / TIMEPREC) + CHAPTER_HEADER_SIZE * (1 + chapter_idx); + + // reinit read state + avio_seek(s->pb, chapter_start + chapter_pos, SEEK_SET); + c->current_codec_second_size = c->codec_second_size; + c->current_chapter_size = chapter_size - chapter_pos; + c->chapter_idx = 1 + chapter_idx; + + // for unaligned frames, estimate offset of first frame in block (assume no padding) + if (s->streams[0]->codecpar->codec_id == AV_CODEC_ID_MP3) { + c->seek_offset = (MP3_FRAME_SIZE - chapter_pos % MP3_FRAME_SIZE) % MP3_FRAME_SIZE; + } + + ff_update_cur_dts(s, s->streams[0], ch->start + (chapter_pos + c->seek_offset) * TIMEPREC); + + return 1; +} + static int aa_probe(AVProbeData *p) { uint8_t *buf = p->buf; @@ -305,6 +405,7 @@ AVInputFormat ff_aa_demuxer = { .read_probe = aa_probe, .read_header = aa_read_header, .read_packet = aa_read_packet, + .read_seek = aa_read_seek, .read_close = aa_read_close, - .flags = AVFMT_GENERIC_INDEX, + .flags = AVFMT_NO_BYTE_SEEK | AVFMT_NOGENSEARCH, };