/*
  * 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);
 

         if (ff_alloc_extradata(st->codec, ALAC_HEADER))

             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);

         }

     } else {

         if (ff_alloc_extradata(st->codec, size))

             return AVERROR(ENOMEM);

         avio_read(pb, st->codec->extradata, 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 },

 };