/*
  * QCP format (.qcp) demuxer
  * Copyright (c) 2009 Kenan Gillet
  *
  * 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

  * QCP format (.qcp) demuxer
  * @author Kenan Gillet

  * @see RFC 3625: "The QCP File Format and Media Types for Speech Data"

  *     http://tools.ietf.org/html/rfc3625
  */
 

 #include "libavutil/channel_layout.h"

 #include "libavutil/intreadwrite.h"
 #include "avformat.h"
 
 typedef struct {
     uint32_t data_size;                     ///< size of data chunk
 
 #define QCP_MAX_MODE 4
     int16_t rates_per_mode[QCP_MAX_MODE+1]; ///< contains the packet size corresponding
                                             ///< to each mode, -1 if no size.
 } QCPContext;
 
 /**
  * Last 15 out of 16 bytes of QCELP-13K GUID, as stored in the file;
  * the first byte of the GUID can be either 0x41 or 0x42.
  */
 static const uint8_t guid_qcelp_13k_part[15] = {
     0x6d, 0x7f, 0x5e, 0x15, 0xb1, 0xd0, 0x11, 0xba,
     0x91, 0x00, 0x80, 0x5f, 0xb4, 0xb9, 0x7e
 };
 
 /**
  * EVRC GUID as stored in the file
  */
 static const uint8_t guid_evrc[16] = {
     0x8d, 0xd4, 0x89, 0xe6, 0x76, 0x90, 0xb5, 0x46,
     0x91, 0xef, 0x73, 0x6a, 0x51, 0x00, 0xce, 0xb4
 };
 
 /**
  * SMV GUID as stored in the file
  */
 static const uint8_t guid_smv[16] = {
     0x75, 0x2b, 0x7c, 0x8d, 0x97, 0xa7, 0x49, 0xed,
     0x98, 0x5e, 0xd5, 0x3c, 0x8c, 0xc7, 0x5f, 0x84
 };
 
 /**
  * @param guid contains at least 16 bytes
  * @return 1 if the guid is a qcelp_13k guid, 0 otherwise
  */
 static int is_qcelp_13k_guid(const uint8_t *guid) {
     return (guid[0] == 0x41 || guid[0] == 0x42)
         && !memcmp(guid+1, guid_qcelp_13k_part, sizeof(guid_qcelp_13k_part));
 }
 
 static int qcp_probe(AVProbeData *pd)
 {
     if (AV_RL32(pd->buf  ) == AV_RL32("RIFF") &&
         AV_RL64(pd->buf+8) == AV_RL64("QLCMfmt "))
         return AVPROBE_SCORE_MAX;
     return 0;
 }
 

 static int qcp_read_header(AVFormatContext *s)

 {

     AVIOContext *pb = s->pb;

     QCPContext    *c  = s->priv_data;

     AVStream      *st = avformat_new_stream(s, NULL);

     uint8_t       buf[16];
     int           i, nb_rates;
 
     if (!st)
         return AVERROR(ENOMEM);
 

     avio_rb32(pb);                    // "RIFF"

     avio_skip(pb, 4 + 8 + 4 + 1 + 1);    // filesize + "QLCMfmt " + chunk-size + major-version + minor-version

     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

     st->codec->channels   = 1;

     st->codec->channel_layout = AV_CH_LAYOUT_MONO;

     avio_read(pb, buf, 16);

     if (is_qcelp_13k_guid(buf)) {

         st->codec->codec_id = AV_CODEC_ID_QCELP;

     } else if (!memcmp(buf, guid_evrc, 16)) {

         st->codec->codec_id = AV_CODEC_ID_EVRC;

     } else if (!memcmp(buf, guid_smv, 16)) {

         st->codec->codec_id = AV_CODEC_ID_SMV;

     } else {
         av_log(s, AV_LOG_ERROR, "Unknown codec GUID.\n");
         return AVERROR_INVALIDDATA;
     }

     avio_skip(pb, 2 + 80); // codec-version + codec-name

     st->codec->bit_rate = avio_rl16(pb);

     s->packet_size = avio_rl16(pb);

     avio_skip(pb, 2); // block-size

     st->codec->sample_rate = avio_rl16(pb);

     avio_skip(pb, 2); // sample-size

 
     memset(c->rates_per_mode, -1, sizeof(c->rates_per_mode));

     nb_rates = avio_rl32(pb);

     nb_rates = FFMIN(nb_rates, 8);
     for (i=0; i<nb_rates; i++) {

         int size = avio_r8(pb);
         int mode = avio_r8(pb);

         if (mode > QCP_MAX_MODE) {
             av_log(s, AV_LOG_WARNING, "Unknown entry %d=>%d in rate-map-table.\n ", mode, size);
         } else
             c->rates_per_mode[mode] = size;
     }

     avio_skip(pb, 16 - 2*nb_rates + 20); // empty entries of rate-map-table + reserved

 
     return 0;
 }
 
 static int qcp_read_packet(AVFormatContext *s, AVPacket *pkt)
 {

     AVIOContext *pb = s->pb;

     QCPContext    *c  = s->priv_data;
     unsigned int  chunk_size, tag;
 
     while(!url_feof(pb)) {
         if (c->data_size) {

             int pkt_size, ret, mode = avio_r8(pb);

 
             if (s->packet_size) {
                 pkt_size = s->packet_size - 1;
             } else if (mode > QCP_MAX_MODE || (pkt_size = c->rates_per_mode[mode]) < 0) {
                 c->data_size--;
                 continue;
             }
 
             if (c->data_size <= pkt_size) {
                 av_log(s, AV_LOG_WARNING, "Data chunk is too small.\n");
                 pkt_size = c->data_size - 1;
             }
 
             if ((ret = av_get_packet(pb, pkt, pkt_size)) >= 0) {
                 if (pkt_size != ret)
                     av_log(s, AV_LOG_ERROR, "Packet size is too small.\n");
 
                 c->data_size -= pkt_size + 1;
             }
             return ret;
         }
 

         if (avio_tell(pb) & 1 && avio_r8(pb))

             av_log(s, AV_LOG_WARNING, "Padding should be 0.\n");
 

         tag        = avio_rl32(pb);
         chunk_size = avio_rl32(pb);

         switch (tag) {
         case MKTAG('v', 'r', 'a', 't'):

             if (avio_rl32(pb)) // var-rate-flag

                 s->packet_size = 0;

             avio_skip(pb, 4); // size-in-packets

             break;
         case MKTAG('d', 'a', 't', 'a'):
             c->data_size = chunk_size;
             break;
 
         default:

             avio_skip(pb, chunk_size);

         }
     }
     return AVERROR_EOF;
 }
 

 AVInputFormat ff_qcp_demuxer = {

     .name           = "qcp",

     .long_name      = NULL_IF_CONFIG_SMALL("QCP"),

     .priv_data_size = sizeof(QCPContext),
     .read_probe     = qcp_probe,
     .read_header    = qcp_read_header,
     .read_packet    = qcp_read_packet,
 };