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Diffstat (limited to 'ffmpeg/libavformat/cafdec.c')
| -rw-r--r-- | ffmpeg/libavformat/cafdec.c | 434 |
1 files changed, 434 insertions, 0 deletions
diff --git a/ffmpeg/libavformat/cafdec.c b/ffmpeg/libavformat/cafdec.c new file mode 100644 index 0000000..337758e --- /dev/null +++ b/ffmpeg/libavformat/cafdec.c @@ -0,0 +1,434 @@ +/* + * Core Audio Format demuxer + * Copyright (c) 2007 Justin Ruggles + * Copyright (c) 2009 Peter Ross + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/** + * @file + * Core Audio Format demuxer + */ + +#include "avformat.h" +#include "internal.h" +#include "isom.h" +#include "mov_chan.h" +#include "libavutil/intreadwrite.h" +#include "libavutil/intfloat.h" +#include "libavutil/dict.h" +#include "caf.h" + +typedef struct { + int bytes_per_packet; ///< bytes in a packet, or 0 if variable + int frames_per_packet; ///< frames in a packet, or 0 if variable + int64_t num_bytes; ///< total number of bytes in stream + + int64_t packet_cnt; ///< packet counter + int64_t frame_cnt; ///< frame counter + + int64_t data_start; ///< data start position, in bytes + int64_t data_size; ///< raw data size, in bytes +} CaffContext; + +static int probe(AVProbeData *p) +{ + if (AV_RB32(p->buf) == MKBETAG('c','a','f','f') && AV_RB16(&p->buf[4]) == 1) + return AVPROBE_SCORE_MAX; + return 0; +} + +/** Read audio description chunk */ +static int read_desc_chunk(AVFormatContext *s) +{ + AVIOContext *pb = s->pb; + CaffContext *caf = s->priv_data; + AVStream *st; + int flags; + + /* new audio stream */ + st = avformat_new_stream(s, NULL); + if (!st) + return AVERROR(ENOMEM); + + /* parse format description */ + st->codec->codec_type = AVMEDIA_TYPE_AUDIO; + st->codec->sample_rate = av_int2double(avio_rb64(pb)); + st->codec->codec_tag = avio_rl32(pb); + flags = avio_rb32(pb); + caf->bytes_per_packet = avio_rb32(pb); + st->codec->block_align = caf->bytes_per_packet; + caf->frames_per_packet = avio_rb32(pb); + st->codec->channels = avio_rb32(pb); + st->codec->bits_per_coded_sample = avio_rb32(pb); + + /* calculate bit rate for constant size packets */ + if (caf->frames_per_packet > 0 && caf->bytes_per_packet > 0) { + st->codec->bit_rate = (uint64_t)st->codec->sample_rate * (uint64_t)caf->bytes_per_packet * 8 + / (uint64_t)caf->frames_per_packet; + } else { + st->codec->bit_rate = 0; + } + + /* determine codec */ + if (st->codec->codec_tag == MKTAG('l','p','c','m')) + st->codec->codec_id = ff_mov_get_lpcm_codec_id(st->codec->bits_per_coded_sample, (flags ^ 0x2) | 0x4); + else + st->codec->codec_id = ff_codec_get_id(ff_codec_caf_tags, st->codec->codec_tag); + return 0; +} + +/** Read magic cookie chunk */ +static int read_kuki_chunk(AVFormatContext *s, int64_t size) +{ + AVIOContext *pb = s->pb; + AVStream *st = s->streams[0]; + + if (size < 0 || size > INT_MAX - FF_INPUT_BUFFER_PADDING_SIZE) + return -1; + + if (st->codec->codec_id == AV_CODEC_ID_AAC) { + /* The magic cookie format for AAC is an mp4 esds atom. + The lavc AAC decoder requires the data from the codec specific + description as extradata input. */ + int strt, skip; + MOVAtom atom; + + strt = avio_tell(pb); + ff_mov_read_esds(s, pb, atom); + skip = size - (avio_tell(pb) - strt); + if (skip < 0 || !st->codec->extradata || + st->codec->codec_id != AV_CODEC_ID_AAC) { + av_log(s, AV_LOG_ERROR, "invalid AAC magic cookie\n"); + return AVERROR_INVALIDDATA; + } + avio_skip(pb, skip); + } else if (st->codec->codec_id == AV_CODEC_ID_ALAC) { +#define ALAC_PREAMBLE 12 +#define ALAC_HEADER 36 +#define ALAC_NEW_KUKI 24 + uint8_t preamble[12]; + if (size < ALAC_NEW_KUKI) { + av_log(s, AV_LOG_ERROR, "invalid ALAC magic cookie\n"); + avio_skip(pb, size); + return AVERROR_INVALIDDATA; + } + avio_read(pb, preamble, ALAC_PREAMBLE); + + st->codec->extradata = av_mallocz(ALAC_HEADER + FF_INPUT_BUFFER_PADDING_SIZE); + if (!st->codec->extradata) + return AVERROR(ENOMEM); + + /* For the old style cookie, we skip 12 bytes, then read 36 bytes. + * The new style cookie only contains the last 24 bytes of what was + * 36 bytes in the old style cookie, so we fabricate the first 12 bytes + * in that case to maintain compatibility. */ + if (!memcmp(&preamble[4], "frmaalac", 8)) { + if (size < ALAC_PREAMBLE + ALAC_HEADER) { + av_log(s, AV_LOG_ERROR, "invalid ALAC magic cookie\n"); + av_freep(&st->codec->extradata); + return AVERROR_INVALIDDATA; + } + avio_read(pb, st->codec->extradata, ALAC_HEADER); + avio_skip(pb, size - ALAC_PREAMBLE - ALAC_HEADER); + } else { + AV_WB32(st->codec->extradata, 36); + memcpy(&st->codec->extradata[4], "alac", 4); + AV_WB32(&st->codec->extradata[8], 0); + memcpy(&st->codec->extradata[12], preamble, 12); + avio_read(pb, &st->codec->extradata[24], ALAC_NEW_KUKI - 12); + avio_skip(pb, size - ALAC_NEW_KUKI); + } + st->codec->extradata_size = ALAC_HEADER; + } else { + st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE); + if (!st->codec->extradata) + return AVERROR(ENOMEM); + avio_read(pb, st->codec->extradata, size); + st->codec->extradata_size = size; + } + + return 0; +} + +/** Read packet table chunk */ +static int read_pakt_chunk(AVFormatContext *s, int64_t size) +{ + AVIOContext *pb = s->pb; + AVStream *st = s->streams[0]; + CaffContext *caf = s->priv_data; + int64_t pos = 0, ccount, num_packets; + int i; + + ccount = avio_tell(pb); + + num_packets = avio_rb64(pb); + if (num_packets < 0 || INT32_MAX / sizeof(AVIndexEntry) < num_packets) + return AVERROR_INVALIDDATA; + + st->nb_frames = avio_rb64(pb); /* valid frames */ + st->nb_frames += avio_rb32(pb); /* priming frames */ + st->nb_frames += avio_rb32(pb); /* remainder frames */ + + st->duration = 0; + for (i = 0; i < num_packets; i++) { + av_add_index_entry(s->streams[0], pos, st->duration, 0, 0, AVINDEX_KEYFRAME); + pos += caf->bytes_per_packet ? caf->bytes_per_packet : ff_mp4_read_descr_len(pb); + st->duration += caf->frames_per_packet ? caf->frames_per_packet : ff_mp4_read_descr_len(pb); + } + + if (avio_tell(pb) - ccount > size) { + av_log(s, AV_LOG_ERROR, "error reading packet table\n"); + return AVERROR_INVALIDDATA; + } + avio_skip(pb, ccount + size - avio_tell(pb)); + + caf->num_bytes = pos; + return 0; +} + +/** Read information chunk */ +static void read_info_chunk(AVFormatContext *s, int64_t size) +{ + AVIOContext *pb = s->pb; + unsigned int i; + unsigned int nb_entries = avio_rb32(pb); + for (i = 0; i < nb_entries; i++) { + char key[32]; + char value[1024]; + avio_get_str(pb, INT_MAX, key, sizeof(key)); + avio_get_str(pb, INT_MAX, value, sizeof(value)); + av_dict_set(&s->metadata, key, value, 0); + } +} + +static int read_header(AVFormatContext *s) +{ + AVIOContext *pb = s->pb; + CaffContext *caf = s->priv_data; + AVStream *st; + uint32_t tag = 0; + int found_data, ret; + int64_t size, pos; + + avio_skip(pb, 8); /* magic, version, file flags */ + + /* audio description chunk */ + if (avio_rb32(pb) != MKBETAG('d','e','s','c')) { + av_log(s, AV_LOG_ERROR, "desc chunk not present\n"); + return AVERROR_INVALIDDATA; + } + size = avio_rb64(pb); + if (size != 32) + return AVERROR_INVALIDDATA; + + ret = read_desc_chunk(s); + if (ret) + return ret; + st = s->streams[0]; + + /* parse each chunk */ + found_data = 0; + while (!url_feof(pb)) { + + /* stop at data chunk if seeking is not supported or + data chunk size is unknown */ + if (found_data && (caf->data_size < 0 || !pb->seekable)) + break; + + tag = avio_rb32(pb); + size = avio_rb64(pb); + pos = avio_tell(pb); + if (url_feof(pb)) + break; + + switch (tag) { + case MKBETAG('d','a','t','a'): + avio_skip(pb, 4); /* edit count */ + caf->data_start = avio_tell(pb); + caf->data_size = size < 0 ? -1 : size - 4; + if (caf->data_size > 0 && pb->seekable) + avio_skip(pb, caf->data_size); + found_data = 1; + break; + + case MKBETAG('c','h','a','n'): + if ((ret = ff_mov_read_chan(s, s->pb, st, size)) < 0) + return ret; + break; + + /* magic cookie chunk */ + case MKBETAG('k','u','k','i'): + if (read_kuki_chunk(s, size)) + return AVERROR_INVALIDDATA; + break; + + /* packet table chunk */ + case MKBETAG('p','a','k','t'): + if (read_pakt_chunk(s, size)) + return AVERROR_INVALIDDATA; + break; + + case MKBETAG('i','n','f','o'): + read_info_chunk(s, size); + break; + + default: +#define _(x) ((x) >= ' ' ? (x) : ' ') + av_log(s, AV_LOG_WARNING, "skipping CAF chunk: %08X (%c%c%c%c), size %"PRId64"\n", + tag, _(tag>>24), _((tag>>16)&0xFF), _((tag>>8)&0xFF), _(tag&0xFF), size); +#undef _ + case MKBETAG('f','r','e','e'): + if (size < 0) + return AVERROR_INVALIDDATA; + break; + } + + if (size > 0) { + if (pos > INT64_MAX - size) + return AVERROR_INVALIDDATA; + avio_skip(pb, FFMAX(0, pos + size - avio_tell(pb))); + } + } + + if (!found_data) + return AVERROR_INVALIDDATA; + + if (caf->bytes_per_packet > 0 && caf->frames_per_packet > 0) { + if (caf->data_size > 0) + st->nb_frames = (caf->data_size / caf->bytes_per_packet) * caf->frames_per_packet; + } else if (st->nb_index_entries && st->duration > 0) { + st->codec->bit_rate = st->codec->sample_rate * caf->data_size * 8 / + st->duration; + } else { + av_log(s, AV_LOG_ERROR, "Missing packet table. It is required when " + "block size or frame size are variable.\n"); + return AVERROR_INVALIDDATA; + } + + avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate); + st->start_time = 0; + + /* position the stream at the start of data */ + if (caf->data_size >= 0) + avio_seek(pb, caf->data_start, SEEK_SET); + + return 0; +} + +#define CAF_MAX_PKT_SIZE 4096 + +static int read_packet(AVFormatContext *s, AVPacket *pkt) +{ + AVIOContext *pb = s->pb; + AVStream *st = s->streams[0]; + CaffContext *caf = s->priv_data; + int res, pkt_size = 0, pkt_frames = 0; + int64_t left = CAF_MAX_PKT_SIZE; + + if (url_feof(pb)) + return AVERROR_EOF; + + /* don't read past end of data chunk */ + if (caf->data_size > 0) { + left = (caf->data_start + caf->data_size) - avio_tell(pb); + if (!left) + return AVERROR_EOF; + if (left < 0) + return AVERROR(EIO); + } + + pkt_frames = caf->frames_per_packet; + pkt_size = caf->bytes_per_packet; + + if (pkt_size > 0 && pkt_frames == 1) { + pkt_size = (CAF_MAX_PKT_SIZE / pkt_size) * pkt_size; + pkt_size = FFMIN(pkt_size, left); + pkt_frames = pkt_size / caf->bytes_per_packet; + } else if (st->nb_index_entries) { + if (caf->packet_cnt < st->nb_index_entries - 1) { + pkt_size = st->index_entries[caf->packet_cnt + 1].pos - st->index_entries[caf->packet_cnt].pos; + pkt_frames = st->index_entries[caf->packet_cnt + 1].timestamp - st->index_entries[caf->packet_cnt].timestamp; + } else if (caf->packet_cnt == st->nb_index_entries - 1) { + pkt_size = caf->num_bytes - st->index_entries[caf->packet_cnt].pos; + pkt_frames = st->duration - st->index_entries[caf->packet_cnt].timestamp; + } else { + return AVERROR(EIO); + } + } + + if (pkt_size == 0 || pkt_frames == 0 || pkt_size > left) + return AVERROR(EIO); + + res = av_get_packet(pb, pkt, pkt_size); + if (res < 0) + return res; + + pkt->size = res; + pkt->stream_index = 0; + pkt->dts = pkt->pts = caf->frame_cnt; + + caf->packet_cnt++; + caf->frame_cnt += pkt_frames; + + return 0; +} + +static int read_seek(AVFormatContext *s, int stream_index, + int64_t timestamp, int flags) +{ + AVStream *st = s->streams[0]; + CaffContext *caf = s->priv_data; + int64_t pos, packet_cnt, frame_cnt; + + timestamp = FFMAX(timestamp, 0); + + if (caf->frames_per_packet > 0 && caf->bytes_per_packet > 0) { + /* calculate new byte position based on target frame position */ + pos = caf->bytes_per_packet * (timestamp / caf->frames_per_packet); + if (caf->data_size > 0) + pos = FFMIN(pos, caf->data_size); + packet_cnt = pos / caf->bytes_per_packet; + frame_cnt = caf->frames_per_packet * packet_cnt; + } else if (st->nb_index_entries) { + packet_cnt = av_index_search_timestamp(st, timestamp, flags); + frame_cnt = st->index_entries[packet_cnt].timestamp; + pos = st->index_entries[packet_cnt].pos; + } else { + return -1; + } + + if (avio_seek(s->pb, pos + caf->data_start, SEEK_SET) < 0) + return -1; + + caf->packet_cnt = packet_cnt; + caf->frame_cnt = frame_cnt; + + return 0; +} + +AVInputFormat ff_caf_demuxer = { + .name = "caf", + .long_name = NULL_IF_CONFIG_SMALL("Apple CAF (Core Audio Format)"), + .priv_data_size = sizeof(CaffContext), + .read_probe = probe, + .read_header = read_header, + .read_packet = read_packet, + .read_seek = read_seek, + .codec_tag = (const AVCodecTag* const []){ ff_codec_caf_tags, 0 }, +}; |