/*
  * Westwood Studios Multimedia Formats Demuxer (VQA, AUD)
  * Copyright (c) 2003 The ffmpeg Project
  *

  * 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

  * Westwood Studios VQA & AUD file demuxers
  * by Mike Melanson (melanson@pcisys.net)
  * for more information on the Westwood file formats, visit:
  *   http://www.pcisys.net/~melanson/codecs/
  *   http://www.geocities.com/SiliconValley/8682/aud3.txt
  *
  * Implementation note: There is no definite file signature for AUD files.
  * The demuxer uses a probabilistic strategy for content detection. This
  * entails performing sanity checks on certain header values in order to
  * qualify a file. Refer to wsaud_probe() for the precise parameters.
  */
 

 #include "libavutil/intreadwrite.h"

 #include "avformat.h"
 
 #define AUD_HEADER_SIZE 12
 #define AUD_CHUNK_PREAMBLE_SIZE 8
 #define AUD_CHUNK_SIGNATURE 0x0000DEAF
 

 #define FORM_TAG MKBETAG('F', 'O', 'R', 'M')
 #define WVQA_TAG MKBETAG('W', 'V', 'Q', 'A')
 #define VQHD_TAG MKBETAG('V', 'Q', 'H', 'D')
 #define FINF_TAG MKBETAG('F', 'I', 'N', 'F')
 #define SND0_TAG MKBETAG('S', 'N', 'D', '0')

 #define SND1_TAG MKBETAG('S', 'N', 'D', '1')

 #define SND2_TAG MKBETAG('S', 'N', 'D', '2')
 #define VQFR_TAG MKBETAG('V', 'Q', 'F', 'R')

 /* don't know what these tags are for, but acknowledge their existence */

 #define CINF_TAG MKBETAG('C', 'I', 'N', 'F')
 #define CINH_TAG MKBETAG('C', 'I', 'N', 'H')
 #define CIND_TAG MKBETAG('C', 'I', 'N', 'D')
 #define PINF_TAG MKBETAG('P', 'I', 'N', 'F')
 #define PINH_TAG MKBETAG('P', 'I', 'N', 'H')
 #define PIND_TAG MKBETAG('P', 'I', 'N', 'D')

 #define CMDS_TAG MKBETAG('C', 'M', 'D', 'S')

 #define VQA_HEADER_SIZE 0x2A
 #define VQA_FRAMERATE 15
 #define VQA_PREAMBLE_SIZE 8
 
 typedef struct WsAudDemuxContext {
     int audio_samplerate;
     int audio_channels;
     int audio_bits;

     enum CodecID audio_type;

     int audio_stream_index;
     int64_t audio_frame_counter;
 } WsAudDemuxContext;
 
 typedef struct WsVqaDemuxContext {
     int audio_samplerate;
     int audio_channels;
     int audio_bits;
 
     int audio_stream_index;
     int video_stream_index;
 
     int64_t audio_frame_counter;
 } WsVqaDemuxContext;
 
 static int wsaud_probe(AVProbeData *p)
 {
     int field;
 
     /* Probabilistic content detection strategy: There is no file signature
      * so perform sanity checks on various header parameters:
      *   8000 <= sample rate (16 bits) <= 48000  ==> 40001 acceptable numbers

      *   flags <= 0x03 (2 LSBs are used)         ==> 4 acceptable numbers

      *   compression type (8 bits) = 1 or 99     ==> 2 acceptable numbers

      *   first audio chunk signature (32 bits)   ==> 1 acceptable number
      * The number space contains 2^64 numbers. There are 40001 * 4 * 2 * 1 =
      * 320008 acceptable number combinations.

      */
 

     if (p->buf_size < AUD_HEADER_SIZE + AUD_CHUNK_PREAMBLE_SIZE)

         return 0;
 
     /* check sample rate */

     field = AV_RL16(&p->buf[0]);

     if ((field < 8000) || (field > 48000))
         return 0;
 

     /* enforce the rule that the top 6 bits of this flags field are reserved (0);
      * this might not be true, but enforce it until deemed unnecessary */
     if (p->buf[10] & 0xFC)
         return 0;
 

     /* note: only check for WS IMA (type 99) right now since there is no

      * support for type 1 */
     if (p->buf[11] != 99)
         return 0;
 

     /* read ahead to the first audio chunk and validate the first header signature */
     if (AV_RL32(&p->buf[16]) != AUD_CHUNK_SIGNATURE)
         return 0;
 

     /* return 1/2 certainty since this file check is a little sketchy */
     return AVPROBE_SCORE_MAX / 2;
 }
 
 static int wsaud_read_header(AVFormatContext *s,
                              AVFormatParameters *ap)
 {

     WsAudDemuxContext *wsaud = s->priv_data;

     AVIOContext *pb = s->pb;

     AVStream *st;
     unsigned char header[AUD_HEADER_SIZE];
 

     if (avio_read(pb, header, AUD_HEADER_SIZE) != AUD_HEADER_SIZE)

         return AVERROR(EIO);

     wsaud->audio_samplerate = AV_RL16(&header[0]);

     if (header[11] == 99)
         wsaud->audio_type = CODEC_ID_ADPCM_IMA_WS;
     else
         return AVERROR_INVALIDDATA;
 
     /* flag 0 indicates stereo */
     wsaud->audio_channels = (header[10] & 0x1) + 1;
     /* flag 1 indicates 16 bit audio */
     wsaud->audio_bits = (((header[10] & 0x2) >> 1) + 1) * 8;
 
     /* initialize the audio decoder stream */
     st = av_new_stream(s, 0);
     if (!st)

         return AVERROR(ENOMEM);

     av_set_pts_info(st, 33, 1, wsaud->audio_samplerate);

     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

     st->codec->codec_id = wsaud->audio_type;
     st->codec->codec_tag = 0;  /* no tag */
     st->codec->channels = wsaud->audio_channels;
     st->codec->sample_rate = wsaud->audio_samplerate;

     st->codec->bits_per_coded_sample = wsaud->audio_bits;

     st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *

         st->codec->bits_per_coded_sample / 4;
     st->codec->block_align = st->codec->channels * st->codec->bits_per_coded_sample;

 
     wsaud->audio_stream_index = st->index;
     wsaud->audio_frame_counter = 0;
 
     return 0;
 }
 
 static int wsaud_read_packet(AVFormatContext *s,
                              AVPacket *pkt)
 {

     WsAudDemuxContext *wsaud = s->priv_data;

     AVIOContext *pb = s->pb;

     unsigned char preamble[AUD_CHUNK_PREAMBLE_SIZE];
     unsigned int chunk_size;
     int ret = 0;
 

     if (avio_read(pb, preamble, AUD_CHUNK_PREAMBLE_SIZE) !=

         AUD_CHUNK_PREAMBLE_SIZE)

         return AVERROR(EIO);

 
     /* validate the chunk */

     if (AV_RL32(&preamble[4]) != AUD_CHUNK_SIGNATURE)

         return AVERROR_INVALIDDATA;
 

     chunk_size = AV_RL16(&preamble[0]);

     ret= av_get_packet(pb, pkt, chunk_size);
     if (ret != chunk_size)

         return AVERROR(EIO);

     pkt->stream_index = wsaud->audio_stream_index;
     pkt->pts = wsaud->audio_frame_counter;
     pkt->pts /= wsaud->audio_samplerate;
 
     /* 2 samples/byte, 1 or 2 samples per frame depending on stereo */
     wsaud->audio_frame_counter += (chunk_size * 2) / wsaud->audio_channels;
 
     return ret;
 }
 
 static int wsvqa_probe(AVProbeData *p)
 {
     /* need 12 bytes to qualify */
     if (p->buf_size < 12)
         return 0;
 
     /* check for the VQA signatures */

     if ((AV_RB32(&p->buf[0]) != FORM_TAG) ||
         (AV_RB32(&p->buf[8]) != WVQA_TAG))

         return 0;
 
     return AVPROBE_SCORE_MAX;
 }
 
 static int wsvqa_read_header(AVFormatContext *s,
                              AVFormatParameters *ap)
 {

     WsVqaDemuxContext *wsvqa = s->priv_data;

     AVIOContext *pb = s->pb;

     AVStream *st;
     unsigned char *header;
     unsigned char scratch[VQA_PREAMBLE_SIZE];

     unsigned int chunk_tag;
     unsigned int chunk_size;

 
     /* initialize the video decoder stream */
     st = av_new_stream(s, 0);
     if (!st)

         return AVERROR(ENOMEM);

     av_set_pts_info(st, 33, 1, VQA_FRAMERATE);

     wsvqa->video_stream_index = st->index;

     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

     st->codec->codec_id = CODEC_ID_WS_VQA;
     st->codec->codec_tag = 0;  /* no fourcc */

 
     /* skip to the start of the VQA header */

     avio_seek(pb, 20, SEEK_SET);

 
     /* the VQA header needs to go to the decoder */

     st->codec->extradata_size = VQA_HEADER_SIZE;

     st->codec->extradata = av_mallocz(VQA_HEADER_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);

     header = (unsigned char *)st->codec->extradata;

     if (avio_read(pb, st->codec->extradata, VQA_HEADER_SIZE) !=

         VQA_HEADER_SIZE) {

         av_free(st->codec->extradata);

         return AVERROR(EIO);

     }

     st->codec->width = AV_RL16(&header[6]);
     st->codec->height = AV_RL16(&header[8]);

     /* initialize the audio decoder stream for VQA v1 or nonzero samplerate */

     if (AV_RL16(&header[24]) || (AV_RL16(&header[0]) == 1 && AV_RL16(&header[2]) == 1)) {

         st = av_new_stream(s, 0);
         if (!st)

             return AVERROR(ENOMEM);

         av_set_pts_info(st, 33, 1, VQA_FRAMERATE);

         st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

         if (AV_RL16(&header[0]) == 1)

             st->codec->codec_id = CODEC_ID_WESTWOOD_SND1;
         else
             st->codec->codec_id = CODEC_ID_ADPCM_IMA_WS;

         st->codec->codec_tag = 0;  /* no tag */

         st->codec->sample_rate = AV_RL16(&header[24]);

         if (!st->codec->sample_rate)
             st->codec->sample_rate = 22050;

         st->codec->channels = header[26];

         if (!st->codec->channels)
             st->codec->channels = 1;

         st->codec->bits_per_coded_sample = 16;

         st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *

             st->codec->bits_per_coded_sample / 4;
         st->codec->block_align = st->codec->channels * st->codec->bits_per_coded_sample;

 
         wsvqa->audio_stream_index = st->index;

         wsvqa->audio_samplerate = st->codec->sample_rate;
         wsvqa->audio_channels = st->codec->channels;

         wsvqa->audio_frame_counter = 0;
     }

     /* there are 0 or more chunks before the FINF chunk; iterate until
      * FINF has been skipped and the file will be ready to be demuxed */
     do {

         if (avio_read(pb, scratch, VQA_PREAMBLE_SIZE) != VQA_PREAMBLE_SIZE)

             return AVERROR(EIO);

         chunk_tag = AV_RB32(&scratch[0]);
         chunk_size = AV_RB32(&scratch[4]);

 
         /* catch any unknown header tags, for curiousity */
         switch (chunk_tag) {
         case CINF_TAG:
         case CINH_TAG:
         case CIND_TAG:
         case PINF_TAG:
         case PINH_TAG:
         case PIND_TAG:
         case FINF_TAG:

         case CMDS_TAG:

             break;
 
         default:

             av_log (s, AV_LOG_ERROR, " note: unknown chunk seen (%c%c%c%c)\n",

                 scratch[0], scratch[1],
                 scratch[2], scratch[3]);
             break;
         }
 

         avio_skip(pb, chunk_size);

     } while (chunk_tag != FINF_TAG);

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

     WsVqaDemuxContext *wsvqa = s->priv_data;

     AVIOContext *pb = s->pb;

     int ret = -1;

     unsigned char preamble[VQA_PREAMBLE_SIZE];
     unsigned int chunk_type;
     unsigned int chunk_size;
     int skip_byte;
 

     while (avio_read(pb, preamble, VQA_PREAMBLE_SIZE) == VQA_PREAMBLE_SIZE) {

         chunk_type = AV_RB32(&preamble[0]);
         chunk_size = AV_RB32(&preamble[4]);

         skip_byte = chunk_size & 0x01;
 
         if ((chunk_type == SND1_TAG) || (chunk_type == SND2_TAG) || (chunk_type == VQFR_TAG)) {
 
             if (av_new_packet(pkt, chunk_size))

                 return AVERROR(EIO);

             ret = avio_read(pb, pkt->data, chunk_size);

             if (ret != chunk_size) {
                 av_free_packet(pkt);

                 return AVERROR(EIO);

             }
 
             if (chunk_type == SND2_TAG) {
                 pkt->stream_index = wsvqa->audio_stream_index;
                 /* 2 samples/byte, 1 or 2 samples per frame depending on stereo */
                 wsvqa->audio_frame_counter += (chunk_size * 2) / wsvqa->audio_channels;
             } else if(chunk_type == SND1_TAG) {
                 pkt->stream_index = wsvqa->audio_stream_index;
                 /* unpacked size is stored in header */

                 wsvqa->audio_frame_counter += AV_RL16(pkt->data) / wsvqa->audio_channels;

             } else {
                 pkt->stream_index = wsvqa->video_stream_index;
             }
             /* stay on 16-bit alignment */
             if (skip_byte)

                 avio_skip(pb, 1);

 
             return ret;

         } else {

             switch(chunk_type){
             case CMDS_TAG:
             case SND0_TAG:
                 break;
             default:
                 av_log(s, AV_LOG_INFO, "Skipping unknown chunk 0x%08X\n", chunk_type);
             }

             avio_skip(pb, chunk_size + skip_byte);

         }

     }

 
     return ret;
 }
 

 #if CONFIG_WSAUD_DEMUXER

 AVInputFormat ff_wsaud_demuxer = {

     "wsaud",

     NULL_IF_CONFIG_SMALL("Westwood Studios audio format"),

     sizeof(WsAudDemuxContext),
     wsaud_probe,
     wsaud_read_header,
     wsaud_read_packet,
 };

 #endif

 #if CONFIG_WSVQA_DEMUXER

 AVInputFormat ff_wsvqa_demuxer = {

     "wsvqa",

     NULL_IF_CONFIG_SMALL("Westwood Studios VQA format"),

     sizeof(WsVqaDemuxContext),
     wsvqa_probe,
     wsvqa_read_header,
     wsvqa_read_packet,
 };

 #endif