Core Audio Format demuxer

Originally committed as revision 19879 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 379 insertions, 0 deletions

diff --git a/libavformat/cafdec.c b/libavformat/cafdec.c
new file mode 100644
index 0000000000..c4aad1bbfa
--- /dev/null
+++ b/libavformat/cafdec.c
@@ -0,0 +1,379 @@
+/*
+ * 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 libavformat/cafdec.c
+ * Core Audio Format demuxer
+ */
+
+#include "avformat.h"
+#include "riff.h"
+#include "isom.h"
+#include "libavutil/intreadwrite.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)
+{
+    ByteIOContext *pb = s->pb;
+    CaffContext *caf  = s->priv_data;
+    AVStream *st;
+    int flags;
+
+    /* new audio stream */
+    st = av_new_stream(s, 0);
+    if (!st)
+        return AVERROR_NOMEM;
+
+    /* parse format description */
+    st->codec->codec_type  = CODEC_TYPE_AUDIO;
+    st->codec->sample_rate = av_int2dbl(get_be64(pb));
+    st->codec->codec_tag   = get_be32(pb);
+    flags = get_be32(pb);
+    caf->bytes_per_packet  = get_be32(pb);
+    st->codec->block_align = caf->bytes_per_packet;
+    caf->frames_per_packet = get_be32(pb);
+    st->codec->channels    = get_be32(pb);
+    st->codec->bits_per_coded_sample = get_be32(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 == MKBETAG('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)
+{
+    ByteIOContext *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 == 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 = url_ftell(pb);
+        ff_mov_read_esds(s, pb, atom);
+        skip = size - (url_ftell(pb) - strt);
+        if (skip < 0 || !st->codec->extradata ||
+            st->codec->codec_id != CODEC_ID_AAC) {
+            av_log(s, AV_LOG_ERROR, "invalid AAC magic cookie\n");
+            return AVERROR_INVALIDDATA;
+        }
+        url_fskip(pb, skip);
+    } else {
+        st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
+        if (!st->codec->extradata)
+            return AVERROR(ENOMEM);
+        get_buffer(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)
+{
+    ByteIOContext *pb = s->pb;
+    AVStream *st      = s->streams[0];
+    CaffContext *caf  = s->priv_data;
+    int64_t pos = 0, ccount;
+    int num_packets, i;
+
+    ccount = url_ftell(pb);
+
+    num_packets = get_be64(pb);
+    if (num_packets < 0 || INT32_MAX / sizeof(AVIndexEntry) < num_packets)
+        return AVERROR_INVALIDDATA;
+
+    st->nb_frames  = get_be64(pb); /* valid frames */
+    st->nb_frames += get_be32(pb); /* priming frames */
+    st->nb_frames += get_be32(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 (url_ftell(pb) - ccount != size) {
+        av_log(s, AV_LOG_ERROR, "error reading packet table\n");
+        return -1;
+    }
+
+    caf->num_bytes = pos;
+    return 0;
+}
+
+/** Read information chunk */
+static void read_info_chunk(AVFormatContext *s, int64_t size)
+{
+    ByteIOContext *pb = s->pb;
+    unsigned int i;
+    unsigned int nb_entries = get_be32(pb);
+    for (i = 0; i < nb_entries; i++) {
+        char key[32];
+        char value[1024];
+        get_strz(pb, key, sizeof(key));
+        get_strz(pb, value, sizeof(value));
+        av_metadata_set(&s->metadata, key, value);
+    }
+}
+
+static int read_header(AVFormatContext *s,
+                       AVFormatParameters *ap)
+{
+    ByteIOContext *pb = s->pb;
+    CaffContext *caf  = s->priv_data;
+    AVStream *st;
+    uint32_t tag = 0;
+    int found_data, ret;
+    int64_t size;
+
+    url_fskip(pb, 8); /* magic, version, file flags */
+
+    /* audio description chunk */
+    if (get_be32(pb) != MKBETAG('d','e','s','c')) {
+        av_log(s, AV_LOG_ERROR, "desc chunk not present\n");
+        return AVERROR_INVALIDDATA;
+    }
+    size = get_be64(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 || url_is_streamed(pb)))
+            break;
+
+        tag  = get_be32(pb);
+        size = get_be64(pb);
+        if (url_feof(pb))
+            break;
+
+        switch (tag) {
+        case MKBETAG('d','a','t','a'):
+            url_fskip(pb, 4); /* edit count */
+            caf->data_start = url_ftell(pb);
+            caf->data_size  = size < 0 ? -1 : size - 4;
+            if (caf->data_size > 0 && !url_is_streamed(pb))
+                url_fskip(pb, caf->data_size);
+            found_data = 1;
+            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)\n",
+                tag, _(tag>>24), _((tag>>16)&0xFF), _((tag>>8)&0xFF), _(tag&0xFF));
+#undef _
+        case MKBETAG('f','r','e','e'):
+            if (size < 0)
+                return AVERROR_INVALIDDATA;
+            url_fskip(pb, size);
+            break;
+        }
+    }
+
+    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->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;
+    }
+    s->file_size = url_fsize(pb);
+    s->file_size = FFMAX(0, s->file_size);
+
+    av_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)
+        url_fseek(pb, caf->data_start, SEEK_SET);
+
+    return 0;
+}
+
+#define CAF_MAX_PKT_SIZE 4096
+
+static int read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    ByteIOContext *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_IO;
+
+    /* don't read past end of data chunk */
+    if (caf->data_size > 0) {
+        left = (caf->data_start + caf->data_size) - url_ftell(pb);
+        if (left <= 0)
+            return AVERROR_IO;
+    }
+
+    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_IO;
+        }
+    }
+
+    if (pkt_size == 0 || pkt_frames == 0 || pkt_size > left)
+        return AVERROR_IO;
+
+    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;
+
+    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);
+        caf->packet_cnt = pos / caf->bytes_per_packet;
+        caf->frame_cnt  = caf->frames_per_packet * caf->packet_cnt;
+    } else if (st->nb_index_entries) {
+        caf->packet_cnt = av_index_search_timestamp(st, timestamp, flags);
+        caf->frame_cnt  = st->index_entries[caf->packet_cnt].timestamp;
+        pos             = st->index_entries[caf->packet_cnt].pos;
+    } else {
+        return -1;
+    }
+
+    url_fseek(s->pb, pos + caf->data_start, SEEK_SET);
+    return 0;
+}
+
+AVInputFormat caf_demuxer = {
+    "caf",
+    NULL_IF_CONFIG_SMALL("Apple Core Audio Format"),
+    sizeof(CaffContext),
+    probe,
+    read_header,
+    read_packet,
+    NULL,
+    read_seek,
+    .codec_tag = (const AVCodecTag*[]){ff_codec_caf_tags, 0},
+};