/*
  * RIFF demuxing functions and data
  * Copyright (c) 2000 Fabrice Bellard
  *

  * 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 "libavutil/dict.h"
 #include "libavutil/error.h"
 #include "libavutil/log.h"
 #include "libavutil/mathematics.h"
 #include "libavcodec/avcodec.h"
 #include "libavcodec/bytestream.h"
 #include "avformat.h"
 #include "avio_internal.h"
 #include "riff.h"
 

 int ff_get_guid(AVIOContext *s, ff_asf_guid *g)

 {
     av_assert0(sizeof(*g) == 16); //compiler will optimize this out

     if (avio_read(s, *g, sizeof(*g)) < (int)sizeof(*g)) {

         memset(*g, 0, sizeof(*g));

         return AVERROR_INVALIDDATA;
     }
     return 0;

 }
 

 enum AVCodecID ff_codec_guid_get_id(const AVCodecGuid *guids, ff_asf_guid guid)
 {
     int i;
     for (i = 0; guids[i].id != AV_CODEC_ID_NONE; i++)
         if (!ff_guidcmp(guids[i].guid, guid))
             return guids[i].id;
     return AV_CODEC_ID_NONE;
 }
 
 /* We could be given one of the three possible structures here:
  * WAVEFORMAT, PCMWAVEFORMAT or WAVEFORMATEX. Each structure
  * is an expansion of the previous one with the fields added
  * at the bottom. PCMWAVEFORMAT adds 'WORD wBitsPerSample' and
  * WAVEFORMATEX adds 'WORD  cbSize' and basically makes itself
  * an openended structure.
  */
 
 static void parse_waveformatex(AVIOContext *pb, AVCodecContext *c)
 {
     ff_asf_guid subformat;

     int bps = avio_rl16(pb);
     if (bps)
         c->bits_per_coded_sample = bps;
 

     c->channel_layout        = avio_rl32(pb); /* dwChannelMask */
 
     ff_get_guid(pb, &subformat);
     if (!memcmp(subformat + 4,
                 (const uint8_t[]){ FF_MEDIASUBTYPE_BASE_GUID }, 12)) {
         c->codec_tag = AV_RL32(subformat);
         c->codec_id  = ff_wav_codec_get_id(c->codec_tag,
                                            c->bits_per_coded_sample);
     } else {
         c->codec_id = ff_codec_guid_get_id(ff_codec_wav_guids, subformat);
         if (!c->codec_id)
             av_log(c, AV_LOG_WARNING,
                    "unknown subformat:"FF_PRI_GUID"\n",
                    FF_ARG_GUID(subformat));
     }
 }
 
 int ff_get_wav_header(AVIOContext *pb, AVCodecContext *codec, int size)
 {
     int id;
 
     id                 = avio_rl16(pb);
     codec->codec_type  = AVMEDIA_TYPE_AUDIO;
     codec->channels    = avio_rl16(pb);
     codec->sample_rate = avio_rl32(pb);
     codec->bit_rate    = avio_rl32(pb) * 8;
     codec->block_align = avio_rl16(pb);
     if (size == 14) {  /* We're dealing with plain vanilla WAVEFORMAT */
         codec->bits_per_coded_sample = 8;
     } else
         codec->bits_per_coded_sample = avio_rl16(pb);
     if (id == 0xFFFE) {
         codec->codec_tag = 0;
     } else {
         codec->codec_tag = id;
         codec->codec_id  = ff_wav_codec_get_id(id,
                                                codec->bits_per_coded_sample);
     }
     if (size >= 18) {  /* We're obviously dealing with WAVEFORMATEX */
         int cbSize = avio_rl16(pb); /* cbSize */
         size  -= 18;
         cbSize = FFMIN(size, cbSize);
         if (cbSize >= 22 && id == 0xfffe) { /* WAVEFORMATEXTENSIBLE */
             parse_waveformatex(pb, codec);
             cbSize -= 22;
             size   -= 22;
         }
         if (cbSize > 0) {
             av_free(codec->extradata);

             if (ff_get_extradata(codec, pb, cbSize) < 0)

                 return AVERROR(ENOMEM);
             size -= cbSize;
         }
 
         /* It is possible for the chunk to contain garbage at the end */
         if (size > 0)
             avio_skip(pb, size);
     }

     if (codec->sample_rate <= 0) {
         av_log(NULL, AV_LOG_ERROR,
                "Invalid sample rate: %d\n", codec->sample_rate);
         return AVERROR_INVALIDDATA;
     }

     if (codec->codec_id == AV_CODEC_ID_AAC_LATM) {
         /* Channels and sample_rate values are those prior to applying SBR
          * and/or PS. */
         codec->channels    = 0;
         codec->sample_rate = 0;
     }
     /* override bits_per_coded_sample for G.726 */

     if (codec->codec_id == AV_CODEC_ID_ADPCM_G726 && codec->sample_rate)

         codec->bits_per_coded_sample = codec->bit_rate / codec->sample_rate;
 
     return 0;
 }
 
 enum AVCodecID ff_wav_codec_get_id(unsigned int tag, int bps)
 {
     enum AVCodecID id;
     id = ff_codec_get_id(ff_codec_wav_tags, tag);
     if (id <= 0)
         return id;
 
     if (id == AV_CODEC_ID_PCM_S16LE)
         id = ff_get_pcm_codec_id(bps, 0, 0, ~1);
     else if (id == AV_CODEC_ID_PCM_F32LE)
         id = ff_get_pcm_codec_id(bps, 1, 0,  0);
 
     if (id == AV_CODEC_ID_ADPCM_IMA_WAV && bps == 8)
         id = AV_CODEC_ID_PCM_ZORK;
     return id;
 }
 

 int ff_get_bmp_header(AVIOContext *pb, AVStream *st, unsigned *esize)

 {
     int tag1;

     if(esize) *esize  = avio_rl32(pb);
     else                avio_rl32(pb);

     st->codec->width  = avio_rl32(pb);
     st->codec->height = (int32_t)avio_rl32(pb);
     avio_rl16(pb); /* planes */
     st->codec->bits_per_coded_sample = avio_rl16(pb); /* depth */
     tag1                             = avio_rl32(pb);
     avio_rl32(pb); /* ImageSize */
     avio_rl32(pb); /* XPelsPerMeter */
     avio_rl32(pb); /* YPelsPerMeter */
     avio_rl32(pb); /* ClrUsed */
     avio_rl32(pb); /* ClrImportant */
     return tag1;
 }
 
 int ff_read_riff_info(AVFormatContext *s, int64_t size)
 {
     int64_t start, end, cur;
     AVIOContext *pb = s->pb;
 
     start = avio_tell(pb);
     end   = start + size;
 
     while ((cur = avio_tell(pb)) >= 0 &&
            cur <= end - 8 /* = tag + size */) {
         uint32_t chunk_code;
         int64_t chunk_size;
         char key[5] = { 0 };
         char *value;
 
         chunk_code = avio_rl32(pb);
         chunk_size = avio_rl32(pb);

         if (url_feof(pb)) {
             if (chunk_code || chunk_size) {
                 av_log(s, AV_LOG_WARNING, "INFO subchunk truncated\n");
                 return AVERROR_INVALIDDATA;
             }
             return AVERROR_EOF;
         }

         if (chunk_size > end ||
             end - chunk_size < cur ||
             chunk_size == UINT_MAX) {

             avio_seek(pb, -9, SEEK_CUR);
             chunk_code = avio_rl32(pb);
             chunk_size = avio_rl32(pb);
             if (chunk_size > end || end - chunk_size < cur || chunk_size == UINT_MAX) {
                 av_log(s, AV_LOG_WARNING, "too big INFO subchunk\n");
                 return AVERROR_INVALIDDATA;
             }

         }
 
         chunk_size += (chunk_size & 1);
 
         if (!chunk_code) {
             if (chunk_size)
                 avio_skip(pb, chunk_size);
             else if (pb->eof_reached) {
                 av_log(s, AV_LOG_WARNING, "truncated file\n");
                 return AVERROR_EOF;
             }
             continue;
         }
 

         value = av_mallocz(chunk_size + 1);

         if (!value) {
             av_log(s, AV_LOG_ERROR,
                    "out of memory, unable to read INFO tag\n");
             return AVERROR(ENOMEM);
         }
 
         AV_WL32(key, chunk_code);
 
         if (avio_read(pb, value, chunk_size) != chunk_size) {
             av_log(s, AV_LOG_WARNING,
                    "premature end of file while reading INFO tag\n");
         }
 
         av_dict_set(&s->metadata, key, value, AV_DICT_DONT_STRDUP_VAL);
     }
 
     return 0;
 }