/*
  * Monkey's Audio APE demuxer
  * Copyright (c) 2007 Benjamin Zores <ben@geexbox.org>
  *  based upon libdemac from Dave Chapman.
  *
  * 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
  */
 
 #include <stdio.h>
 

 #include "libavutil/intreadwrite.h"

 #include "avformat.h"

 #include "internal.h"

 #include "apetag.h"

 
 /* The earliest and latest file formats supported by this library */

 #define APE_MIN_VERSION 3800

 #define APE_MAX_VERSION 3990
 
 #define MAC_FORMAT_FLAG_8_BIT                 1 // is 8-bit [OBSOLETE]
 #define MAC_FORMAT_FLAG_CRC                   2 // uses the new CRC32 error detection [OBSOLETE]
 #define MAC_FORMAT_FLAG_HAS_PEAK_LEVEL        4 // uint32 nPeakLevel after the header [OBSOLETE]
 #define MAC_FORMAT_FLAG_24_BIT                8 // is 24-bit [OBSOLETE]
 #define MAC_FORMAT_FLAG_HAS_SEEK_ELEMENTS    16 // has the number of seek elements after the peak level
 #define MAC_FORMAT_FLAG_CREATE_WAV_HEADER    32 // create the wave header on decompression (not stored)
 
 #define APE_EXTRADATA_SIZE 6
 

 typedef struct APEFrame {

     int64_t pos;
     int nblocks;
     int size;
     int skip;
     int64_t pts;
 } APEFrame;
 

 typedef struct APEContext {

     /* Derived fields */
     uint32_t junklength;
     uint32_t firstframe;
     uint32_t totalsamples;
     int currentframe;
     APEFrame *frames;
 
     /* Info from Descriptor Block */
     int16_t fileversion;
     int16_t padding1;
     uint32_t descriptorlength;
     uint32_t headerlength;
     uint32_t seektablelength;
     uint32_t wavheaderlength;
     uint32_t audiodatalength;
     uint32_t audiodatalength_high;
     uint32_t wavtaillength;
     uint8_t md5[16];
 
     /* Info from Header Block */
     uint16_t compressiontype;
     uint16_t formatflags;
     uint32_t blocksperframe;
     uint32_t finalframeblocks;
     uint32_t totalframes;
     uint16_t bps;
     uint16_t channels;
     uint32_t samplerate;
 
     /* Seektable */
     uint32_t *seektable;

     uint8_t  *bittable;

 } APEContext;
 
 static int ape_probe(AVProbeData * p)
 {

     int version = AV_RL16(p->buf+4);
     if (AV_RL32(p->buf) != MKTAG('M', 'A', 'C', ' '))
         return 0;

     if (version < APE_MIN_VERSION || version > APE_MAX_VERSION)
         return AVPROBE_SCORE_MAX/4;
 
     return AVPROBE_SCORE_MAX;

 }
 

 static void ape_dumpinfo(AVFormatContext * s, APEContext * ape_ctx)

 {

 #ifdef DEBUG

     int i;
 

     av_log(s, AV_LOG_DEBUG, "Descriptor Block:\n\n");

     av_log(s, AV_LOG_DEBUG, "fileversion          = %"PRId16"\n", ape_ctx->fileversion);
     av_log(s, AV_LOG_DEBUG, "descriptorlength     = %"PRIu32"\n", ape_ctx->descriptorlength);
     av_log(s, AV_LOG_DEBUG, "headerlength         = %"PRIu32"\n", ape_ctx->headerlength);
     av_log(s, AV_LOG_DEBUG, "seektablelength      = %"PRIu32"\n", ape_ctx->seektablelength);
     av_log(s, AV_LOG_DEBUG, "wavheaderlength      = %"PRIu32"\n", ape_ctx->wavheaderlength);
     av_log(s, AV_LOG_DEBUG, "audiodatalength      = %"PRIu32"\n", ape_ctx->audiodatalength);
     av_log(s, AV_LOG_DEBUG, "audiodatalength_high = %"PRIu32"\n", ape_ctx->audiodatalength_high);
     av_log(s, AV_LOG_DEBUG, "wavtaillength        = %"PRIu32"\n", ape_ctx->wavtaillength);

     av_log(s, AV_LOG_DEBUG, "md5                  = ");

     for (i = 0; i < 16; i++)

          av_log(s, AV_LOG_DEBUG, "%02x", ape_ctx->md5[i]);
     av_log(s, AV_LOG_DEBUG, "\n");

     av_log(s, AV_LOG_DEBUG, "\nHeader Block:\n\n");

     av_log(s, AV_LOG_DEBUG, "compressiontype      = %"PRIu16"\n", ape_ctx->compressiontype);
     av_log(s, AV_LOG_DEBUG, "formatflags          = %"PRIu16"\n", ape_ctx->formatflags);
     av_log(s, AV_LOG_DEBUG, "blocksperframe       = %"PRIu32"\n", ape_ctx->blocksperframe);
     av_log(s, AV_LOG_DEBUG, "finalframeblocks     = %"PRIu32"\n", ape_ctx->finalframeblocks);
     av_log(s, AV_LOG_DEBUG, "totalframes          = %"PRIu32"\n", ape_ctx->totalframes);
     av_log(s, AV_LOG_DEBUG, "bps                  = %"PRIu16"\n", ape_ctx->bps);
     av_log(s, AV_LOG_DEBUG, "channels             = %"PRIu16"\n", ape_ctx->channels);
     av_log(s, AV_LOG_DEBUG, "samplerate           = %"PRIu32"\n", ape_ctx->samplerate);

     av_log(s, AV_LOG_DEBUG, "\nSeektable\n\n");

     if ((ape_ctx->seektablelength / sizeof(uint32_t)) != ape_ctx->totalframes) {

         av_log(s, AV_LOG_DEBUG, "No seektable\n");

     } else {
         for (i = 0; i < ape_ctx->seektablelength / sizeof(uint32_t); i++) {
             if (i < ape_ctx->totalframes - 1) {

                 av_log(s, AV_LOG_DEBUG, "%8d   %"PRIu32" (%"PRIu32" bytes)",

                        i, ape_ctx->seektable[i],
                        ape_ctx->seektable[i + 1] - ape_ctx->seektable[i]);

                 if (ape_ctx->bittable)

                     av_log(s, AV_LOG_DEBUG, " + %2d bits\n",
                            ape_ctx->bittable[i]);
                 av_log(s, AV_LOG_DEBUG, "\n");

             } else {

                 av_log(s, AV_LOG_DEBUG, "%8d   %"PRIu32"\n", i, ape_ctx->seektable[i]);

             }
         }
     }
 

     av_log(s, AV_LOG_DEBUG, "\nFrames\n\n");

     for (i = 0; i < ape_ctx->totalframes; i++)

         av_log(s, AV_LOG_DEBUG, "%8d   %8"PRId64" %8d (%d samples)\n", i,
                ape_ctx->frames[i].pos, ape_ctx->frames[i].size,
                ape_ctx->frames[i].nblocks);

     av_log(s, AV_LOG_DEBUG, "\nCalculated information:\n\n");

     av_log(s, AV_LOG_DEBUG, "junklength           = %"PRIu32"\n", ape_ctx->junklength);
     av_log(s, AV_LOG_DEBUG, "firstframe           = %"PRIu32"\n", ape_ctx->firstframe);
     av_log(s, AV_LOG_DEBUG, "totalsamples         = %"PRIu32"\n", ape_ctx->totalsamples);

 #endif

 }
 

 static int ape_read_header(AVFormatContext * s)

 {

     AVIOContext *pb = s->pb;

     APEContext *ape = s->priv_data;
     AVStream *st;
     uint32_t tag;
     int i;

     int total_blocks, final_size = 0;
     int64_t pts, file_size;

     /* Skip any leading junk such as id3v2 tags */
     ape->junklength = avio_tell(pb);

     tag = avio_rl32(pb);

     if (tag != MKTAG('M', 'A', 'C', ' '))

         return AVERROR_INVALIDDATA;

     ape->fileversion = avio_rl16(pb);

 
     if (ape->fileversion < APE_MIN_VERSION || ape->fileversion > APE_MAX_VERSION) {

         av_log(s, AV_LOG_ERROR, "Unsupported file version - %d.%02d\n",

                ape->fileversion / 1000, (ape->fileversion % 1000) / 10);

         return AVERROR_PATCHWELCOME;

     }
 
     if (ape->fileversion >= 3980) {

         ape->padding1             = avio_rl16(pb);
         ape->descriptorlength     = avio_rl32(pb);
         ape->headerlength         = avio_rl32(pb);
         ape->seektablelength      = avio_rl32(pb);
         ape->wavheaderlength      = avio_rl32(pb);
         ape->audiodatalength      = avio_rl32(pb);
         ape->audiodatalength_high = avio_rl32(pb);
         ape->wavtaillength        = avio_rl32(pb);
         avio_read(pb, ape->md5, 16);

 
         /* Skip any unknown bytes at the end of the descriptor.
            This is for future compatibility */
         if (ape->descriptorlength > 52)

             avio_skip(pb, ape->descriptorlength - 52);

 
         /* Read header data */

         ape->compressiontype      = avio_rl16(pb);
         ape->formatflags          = avio_rl16(pb);
         ape->blocksperframe       = avio_rl32(pb);
         ape->finalframeblocks     = avio_rl32(pb);
         ape->totalframes          = avio_rl32(pb);
         ape->bps                  = avio_rl16(pb);
         ape->channels             = avio_rl16(pb);
         ape->samplerate           = avio_rl32(pb);

     } else {
         ape->descriptorlength = 0;
         ape->headerlength = 32;
 

         ape->compressiontype      = avio_rl16(pb);
         ape->formatflags          = avio_rl16(pb);
         ape->channels             = avio_rl16(pb);
         ape->samplerate           = avio_rl32(pb);
         ape->wavheaderlength      = avio_rl32(pb);
         ape->wavtaillength        = avio_rl32(pb);
         ape->totalframes          = avio_rl32(pb);
         ape->finalframeblocks     = avio_rl32(pb);

 
         if (ape->formatflags & MAC_FORMAT_FLAG_HAS_PEAK_LEVEL) {

             avio_skip(pb, 4); /* Skip the peak level */

             ape->headerlength += 4;
         }
 
         if (ape->formatflags & MAC_FORMAT_FLAG_HAS_SEEK_ELEMENTS) {

             ape->seektablelength = avio_rl32(pb);

             ape->headerlength += 4;
             ape->seektablelength *= sizeof(int32_t);
         } else
             ape->seektablelength = ape->totalframes * sizeof(int32_t);
 
         if (ape->formatflags & MAC_FORMAT_FLAG_8_BIT)
             ape->bps = 8;
         else if (ape->formatflags & MAC_FORMAT_FLAG_24_BIT)
             ape->bps = 24;
         else
             ape->bps = 16;
 
         if (ape->fileversion >= 3950)
             ape->blocksperframe = 73728 * 4;
         else if (ape->fileversion >= 3900 || (ape->fileversion >= 3800  && ape->compressiontype >= 4000))
             ape->blocksperframe = 73728;
         else
             ape->blocksperframe = 9216;
 
         /* Skip any stored wav header */
         if (!(ape->formatflags & MAC_FORMAT_FLAG_CREATE_WAV_HEADER))

             avio_skip(pb, ape->wavheaderlength);

     }
 

     if(!ape->totalframes){
         av_log(s, AV_LOG_ERROR, "No frames in the file!\n");
         return AVERROR(EINVAL);
     }

     if(ape->totalframes > UINT_MAX / sizeof(APEFrame)){

         av_log(s, AV_LOG_ERROR, "Too many frames: %"PRIu32"\n",
                ape->totalframes);

         return AVERROR_INVALIDDATA;

     }

     if (ape->seektablelength / sizeof(*ape->seektable) < ape->totalframes) {

         av_log(s, AV_LOG_ERROR,

                "Number of seek entries is less than number of frames: %"SIZE_SPECIFIER" vs. %"PRIu32"\n",

                ape->seektablelength / sizeof(*ape->seektable), ape->totalframes);
         return AVERROR_INVALIDDATA;
     }

     ape->frames       = av_malloc_array(ape->totalframes, sizeof(APEFrame));

     if(!ape->frames)

         return AVERROR(ENOMEM);

     ape->firstframe   = ape->junklength + ape->descriptorlength + ape->headerlength + ape->seektablelength + ape->wavheaderlength;

     if (ape->fileversion < 3810)
         ape->firstframe += ape->totalframes;

     ape->currentframe = 0;
 
 
     ape->totalsamples = ape->finalframeblocks;
     if (ape->totalframes > 1)
         ape->totalsamples += ape->blocksperframe * (ape->totalframes - 1);
 
     if (ape->seektablelength > 0) {

         ape->seektable = av_mallocz(ape->seektablelength);

         if (!ape->seektable)
             return AVERROR(ENOMEM);

         for (i = 0; i < ape->seektablelength / sizeof(uint32_t) && !pb->eof_reached; i++)

             ape->seektable[i] = avio_rl32(pb);

         if (ape->fileversion < 3810) {

             ape->bittable = av_mallocz(ape->totalframes);

             if (!ape->bittable)
                 return AVERROR(ENOMEM);

             for (i = 0; i < ape->totalframes && !pb->eof_reached; i++)

                 ape->bittable[i] = avio_r8(pb);
         }

         if (pb->eof_reached)
             av_log(s, AV_LOG_WARNING, "File truncated\n");

     }
 
     ape->frames[0].pos     = ape->firstframe;
     ape->frames[0].nblocks = ape->blocksperframe;
     ape->frames[0].skip    = 0;
     for (i = 1; i < ape->totalframes; i++) {

         ape->frames[i].pos      = ape->seektable[i] + ape->junklength;

         ape->frames[i].nblocks  = ape->blocksperframe;
         ape->frames[i - 1].size = ape->frames[i].pos - ape->frames[i - 1].pos;
         ape->frames[i].skip     = (ape->frames[i].pos - ape->frames[0].pos) & 3;
     }
     ape->frames[ape->totalframes - 1].nblocks = ape->finalframeblocks;

     /* calculate final packet size from total file size, if available */
     file_size = avio_size(pb);
     if (file_size > 0) {
         final_size = file_size - ape->frames[ape->totalframes - 1].pos -
                      ape->wavtaillength;
         final_size -= final_size & 3;
     }
     if (file_size <= 0 || final_size <= 0)
         final_size = ape->finalframeblocks * 8;
     ape->frames[ape->totalframes - 1].size = final_size;

 
     for (i = 0; i < ape->totalframes; i++) {
         if(ape->frames[i].skip){
             ape->frames[i].pos  -= ape->frames[i].skip;
             ape->frames[i].size += ape->frames[i].skip;
         }
         ape->frames[i].size = (ape->frames[i].size + 3) & ~3;
     }

     if (ape->fileversion < 3810) {
         for (i = 0; i < ape->totalframes; i++) {
             if (i < ape->totalframes - 1 && ape->bittable[i + 1])
                 ape->frames[i].size += 4;
             ape->frames[i].skip <<= 3;
             ape->frames[i].skip  += ape->bittable[i];
         }
     }

     ape_dumpinfo(s, ape);

     av_log(s, AV_LOG_VERBOSE, "Decoding file - v%d.%02d, compression level %"PRIu16"\n",

            ape->fileversion / 1000, (ape->fileversion % 1000) / 10,
            ape->compressiontype);

 
     /* now we are ready: build format streams */

     st = avformat_new_stream(s, NULL);

     if (!st)

         return AVERROR(ENOMEM);

 
     total_blocks = (ape->totalframes == 0) ? 0 : ((ape->totalframes - 1) * ape->blocksperframe) + ape->finalframeblocks;
 

     st->codecpar->codec_type      = AVMEDIA_TYPE_AUDIO;
     st->codecpar->codec_id        = AV_CODEC_ID_APE;
     st->codecpar->codec_tag       = MKTAG('A', 'P', 'E', ' ');
     st->codecpar->channels        = ape->channels;
     st->codecpar->sample_rate     = ape->samplerate;
     st->codecpar->bits_per_coded_sample = ape->bps;

 
     st->nb_frames = ape->totalframes;

     st->start_time = 0;

     st->duration  = total_blocks;
     avpriv_set_pts_info(st, 64, 1, ape->samplerate);

     if (ff_alloc_extradata(st->codecpar, APE_EXTRADATA_SIZE))

         return AVERROR(ENOMEM);

     AV_WL16(st->codecpar->extradata + 0, ape->fileversion);
     AV_WL16(st->codecpar->extradata + 2, ape->compressiontype);
     AV_WL16(st->codecpar->extradata + 4, ape->formatflags);

 
     pts = 0;
     for (i = 0; i < ape->totalframes; i++) {
         ape->frames[i].pts = pts;
         av_add_index_entry(st, ape->frames[i].pos, ape->frames[i].pts, 0, 0, AVINDEX_KEYFRAME);

         pts += ape->blocksperframe;

     }
 

     /* try to read APE tags */

     if (pb->seekable & AVIO_SEEKABLE_NORMAL) {

         ff_ape_parse_tag(s);
         avio_seek(pb, 0, SEEK_SET);
     }
 

     return 0;
 }
 
 static int ape_read_packet(AVFormatContext * s, AVPacket * pkt)
 {
     int ret;
     int nblocks;
     APEContext *ape = s->priv_data;
     uint32_t extra_size = 8;
 

     if (avio_feof(s->pb))

         return AVERROR_EOF;

     if (ape->currentframe >= ape->totalframes)

         return AVERROR_EOF;

     if (avio_seek(s->pb, ape->frames[ape->currentframe].pos, SEEK_SET) < 0)
         return AVERROR(EIO);

 
     /* Calculate how many blocks there are in this frame */
     if (ape->currentframe == (ape->totalframes - 1))
         nblocks = ape->finalframeblocks;
     else
         nblocks = ape->blocksperframe;
 

     if (ape->frames[ape->currentframe].size <= 0 ||
         ape->frames[ape->currentframe].size > INT_MAX - extra_size) {
         av_log(s, AV_LOG_ERROR, "invalid packet size: %d\n",
                ape->frames[ape->currentframe].size);
         ape->currentframe++;
         return AVERROR(EIO);
     }
 

     if (av_new_packet(pkt,  ape->frames[ape->currentframe].size + extra_size) < 0)

         return AVERROR(ENOMEM);

 
     AV_WL32(pkt->data    , nblocks);
     AV_WL32(pkt->data + 4, ape->frames[ape->currentframe].skip);

     ret = avio_read(s->pb, pkt->data + extra_size, ape->frames[ape->currentframe].size);

     if (ret < 0) {

         av_packet_unref(pkt);

         return ret;

     }

 
     pkt->pts = ape->frames[ape->currentframe].pts;
     pkt->stream_index = 0;
 
     /* note: we need to modify the packet size here to handle the last
        packet */
     pkt->size = ret + extra_size;
 
     ape->currentframe++;
 
     return 0;
 }
 
 static int ape_read_close(AVFormatContext * s)
 {
     APEContext *ape = s->priv_data;
 
     av_freep(&ape->frames);
     av_freep(&ape->seektable);

     av_freep(&ape->bittable);

     return 0;
 }
 
 static int ape_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
 {
     AVStream *st = s->streams[stream_index];
     APEContext *ape = s->priv_data;
     int index = av_index_search_timestamp(st, timestamp, flags);
 
     if (index < 0)
         return -1;
 

     if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
         return -1;

     ape->currentframe = index;
     return 0;
 }
 

 AVInputFormat ff_ape_demuxer = {

     .name           = "ape",
     .long_name      = NULL_IF_CONFIG_SMALL("Monkey's Audio"),
     .priv_data_size = sizeof(APEContext),
     .read_probe     = ape_probe,
     .read_header    = ape_read_header,
     .read_packet    = ape_read_packet,
     .read_close     = ape_read_close,
     .read_seek      = ape_read_seek,

     .extensions     = "ape,apl,mac",

 };