/*
  * 4X Technologies .4xm File Demuxer (no muxer)

  * 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

  * 4X Technologies file demuxer
  * by Mike Melanson (melanson@pcisys.net)
  * for more information on the .4xm file format, visit:
  *   http://www.pcisys.net/~melanson/codecs/
  */
 

 #include "libavutil/intreadwrite.h"

 #include "libavutil/intfloat.h"

 #include "avformat.h"

 #include "internal.h"

 #define     RIFF_TAG MKTAG('R', 'I', 'F', 'F')

 #define  FOURXMV_TAG MKTAG('4', 'X', 'M', 'V')

 #define     LIST_TAG MKTAG('L', 'I', 'S', 'T')
 #define     HEAD_TAG MKTAG('H', 'E', 'A', 'D')
 #define     TRK__TAG MKTAG('T', 'R', 'K', '_')
 #define     MOVI_TAG MKTAG('M', 'O', 'V', 'I')
 #define     VTRK_TAG MKTAG('V', 'T', 'R', 'K')
 #define     STRK_TAG MKTAG('S', 'T', 'R', 'K')
 #define     std__TAG MKTAG('s', 't', 'd', '_')
 #define     name_TAG MKTAG('n', 'a', 'm', 'e')
 #define     vtrk_TAG MKTAG('v', 't', 'r', 'k')
 #define     strk_TAG MKTAG('s', 't', 'r', 'k')
 #define     ifrm_TAG MKTAG('i', 'f', 'r', 'm')
 #define     pfrm_TAG MKTAG('p', 'f', 'r', 'm')
 #define     cfrm_TAG MKTAG('c', 'f', 'r', 'm')
 #define     ifr2_TAG MKTAG('i', 'f', 'r', '2')
 #define     pfr2_TAG MKTAG('p', 'f', 'r', '2')
 #define     cfr2_TAG MKTAG('c', 'f', 'r', '2')
 #define     snd__TAG MKTAG('s', 'n', 'd', '_')

 
 #define vtrk_SIZE 0x44
 #define strk_SIZE 0x28
 
 #define GET_LIST_HEADER() \

     fourcc_tag = avio_rl32(pb); \

     size       = avio_rl32(pb); \

     if (fourcc_tag != LIST_TAG) \
         return AVERROR_INVALIDDATA; \

     fourcc_tag = avio_rl32(pb);

 
 typedef struct AudioTrack {
     int sample_rate;
     int bits;
     int channels;

     int stream_index;

     int adpcm;

     int64_t audio_pts;

 } AudioTrack;
 
 typedef struct FourxmDemuxContext {

     int video_stream_index;

     int track_count;
     AudioTrack *tracks;

     int64_t video_pts;

     AVRational fps;

 } FourxmDemuxContext;
 
 static int fourxm_probe(AVProbeData *p)
 {

     if ((AV_RL32(&p->buf[0]) != RIFF_TAG) ||

         (AV_RL32(&p->buf[8]) != FOURXMV_TAG))

         return 0;
 
     return AVPROBE_SCORE_MAX;
 }
 

 static int parse_vtrk(AVFormatContext *s,

                       FourxmDemuxContext *fourxm, uint8_t *buf, int size,
                       int left)

 {
     AVStream *st;
     /* check that there is enough data */

     if (size != vtrk_SIZE || left < size + 8) {

         return AVERROR_INVALIDDATA;
     }
 
     /* allocate a new AVStream */
     st = avformat_new_stream(s, NULL);
     if (!st)
         return AVERROR(ENOMEM);
 

     avpriv_set_pts_info(st, 60, fourxm->fps.den, fourxm->fps.num);

 
     fourxm->video_stream_index = st->index;
 
     st->codec->codec_type     = AVMEDIA_TYPE_VIDEO;
     st->codec->codec_id       = AV_CODEC_ID_4XM;

     st->codec->extradata      = av_mallocz(4 + AV_INPUT_BUFFER_PADDING_SIZE);

     if (!st->codec->extradata)
         return AVERROR(ENOMEM);

     st->codec->extradata_size = 4;
     AV_WL32(st->codec->extradata, AV_RL32(buf + 16));
     st->codec->width  = AV_RL32(buf + 36);
     st->codec->height = AV_RL32(buf + 40);
 
     return 0;
 }
 
 
 static int parse_strk(AVFormatContext *s,

                       FourxmDemuxContext *fourxm, uint8_t *buf, int size,
                       int left)

 {
     AVStream *st;
     int track;
     /* check that there is enough data */

     if (size != strk_SIZE || left < size + 8)

         return AVERROR_INVALIDDATA;
 
     track = AV_RL32(buf + 8);

     if ((unsigned)track >= UINT_MAX / sizeof(AudioTrack) - 1) {
         av_log(s, AV_LOG_ERROR, "current_track too large\n");
         return AVERROR_INVALIDDATA;
     }

     if (track + 1 > fourxm->track_count) {
         if (av_reallocp_array(&fourxm->tracks, track + 1, sizeof(AudioTrack)))
             return AVERROR(ENOMEM);
         memset(&fourxm->tracks[fourxm->track_count], 0,
                sizeof(AudioTrack) * (track + 1 - fourxm->track_count));
         fourxm->track_count = track + 1;
     }
     fourxm->tracks[track].adpcm       = AV_RL32(buf + 12);
     fourxm->tracks[track].channels    = AV_RL32(buf + 36);
     fourxm->tracks[track].sample_rate = AV_RL32(buf + 40);
     fourxm->tracks[track].bits        = AV_RL32(buf + 44);
     fourxm->tracks[track].audio_pts   = 0;
 
     if (fourxm->tracks[track].channels    <= 0 ||
         fourxm->tracks[track].sample_rate <= 0 ||

         fourxm->tracks[track].bits        <= 0) {

         av_log(s, AV_LOG_ERROR, "audio header invalid\n");
         return AVERROR_INVALIDDATA;
     }

     if (!fourxm->tracks[track].adpcm && fourxm->tracks[track].bits<8) {
         av_log(s, AV_LOG_ERROR, "bits unspecified for non ADPCM\n");
         return AVERROR_INVALIDDATA;
     }
 

     /* allocate a new AVStream */
     st = avformat_new_stream(s, NULL);
     if (!st)
         return AVERROR(ENOMEM);
 
     st->id = track;
     avpriv_set_pts_info(st, 60, 1, fourxm->tracks[track].sample_rate);
 
     fourxm->tracks[track].stream_index = st->index;
 
     st->codec->codec_type            = AVMEDIA_TYPE_AUDIO;
     st->codec->codec_tag             = 0;
     st->codec->channels              = fourxm->tracks[track].channels;
     st->codec->sample_rate           = fourxm->tracks[track].sample_rate;
     st->codec->bits_per_coded_sample = fourxm->tracks[track].bits;
     st->codec->bit_rate              = st->codec->channels *
                                        st->codec->sample_rate *
                                        st->codec->bits_per_coded_sample;
     st->codec->block_align           = st->codec->channels *
                                        st->codec->bits_per_coded_sample;
 
     if (fourxm->tracks[track].adpcm){
         st->codec->codec_id = AV_CODEC_ID_ADPCM_4XM;
     } else if (st->codec->bits_per_coded_sample == 8) {
         st->codec->codec_id = AV_CODEC_ID_PCM_U8;
     } else
         st->codec->codec_id = AV_CODEC_ID_PCM_S16LE;
 
     return 0;
 }
 

 static int fourxm_read_header(AVFormatContext *s)

 {

     AVIOContext *pb = s->pb;

     unsigned int fourcc_tag;
     unsigned int size;
     int header_size;

     FourxmDemuxContext *fourxm = s->priv_data;

     unsigned char *header;

     int i, ret;

 
     fourxm->track_count = 0;

     fourxm->tracks      = NULL;

     fourxm->fps         = (AVRational){1,1};

 
     /* skip the first 3 32-bit numbers */

     avio_skip(pb, 12);

 
     /* check for LIST-HEAD */
     GET_LIST_HEADER();
     header_size = size - 4;

     if (fourcc_tag != HEAD_TAG || header_size < 0)

         return AVERROR_INVALIDDATA;
 
     /* allocate space for the header and load the whole thing */
     header = av_malloc(header_size);
     if (!header)

         return AVERROR(ENOMEM);

     if (avio_read(pb, header, header_size) != header_size) {

         av_free(header);

         return AVERROR(EIO);

     }

 
     /* take the lazy approach and search for any and all vtrk and strk chunks */
     for (i = 0; i < header_size - 8; i++) {

         fourcc_tag = AV_RL32(&header[i]);

         size       = AV_RL32(&header[i + 4]);

         if (size > header_size - i - 8 && (fourcc_tag == vtrk_TAG || fourcc_tag == strk_TAG)) {
             av_log(s, AV_LOG_ERROR, "chunk larger than array %d>%d\n", size, header_size - i - 8);
             return AVERROR_INVALIDDATA;
         }

         if (fourcc_tag == std__TAG) {

             if (header_size - i < 16) {

                 av_log(s, AV_LOG_ERROR, "std TAG truncated\n");

                 ret = AVERROR_INVALIDDATA;
                 goto fail;

             }

             fourxm->fps = av_d2q(av_int2float(AV_RL32(&header[i + 12])), 10000);

         } else if (fourcc_tag == vtrk_TAG) {

             if ((ret = parse_vtrk(s, fourxm, header + i, size,
                                   header_size - i)) < 0)

                 goto fail;

             i += 8 + size;

         } else if (fourcc_tag == strk_TAG) {

             if ((ret = parse_strk(s, fourxm, header + i, size,
                                   header_size - i)) < 0)

                 goto fail;

             i += 8 + size;

         }
     }
 
     /* skip over the LIST-MOVI chunk (which is where the stream should be */
     GET_LIST_HEADER();

     if (fourcc_tag != MOVI_TAG) {
         ret = AVERROR_INVALIDDATA;

         goto fail;
     }

     av_free(header);

     /* initialize context members */

     fourxm->video_pts = -1;  /* first frame will push to 0 */

     return 0;

 fail:
     av_freep(&fourxm->tracks);
     av_free(header);
     return ret;

 }
 
 static int fourxm_read_packet(AVFormatContext *s,

                               AVPacket *pkt)

 {
     FourxmDemuxContext *fourxm = s->priv_data;

     AVIOContext *pb            = s->pb;

     unsigned int fourcc_tag;

     unsigned int size;

     int ret = 0;

     unsigned int track_number;

     int packet_read = 0;

     unsigned char header[8];

     int audio_frame_count;

 
     while (!packet_read) {

         if ((ret = avio_read(s->pb, header, 8)) < 0)

             return ret;

         fourcc_tag = AV_RL32(&header[0]);

         size       = AV_RL32(&header[4]);

         if (avio_feof(pb))

             return AVERROR(EIO);

         switch (fourcc_tag) {

         case LIST_TAG:

             /* this is a good time to bump the video pts */

             fourxm->video_pts++;

             /* skip the LIST-* tag and move on to the next fourcc */

             avio_rl32(pb);

             break;
 

         case ifrm_TAG:
         case pfrm_TAG:

         case cfrm_TAG:
         case ifr2_TAG:
         case pfr2_TAG:
         case cfr2_TAG:

             /* allocate 8 more bytes than 'size' to account for fourcc
              * and size */

             if (size + 8 < size || av_new_packet(pkt, size + 8))

                 return AVERROR(EIO);

             pkt->stream_index = fourxm->video_stream_index;

             pkt->pts          = fourxm->video_pts;
             pkt->pos          = avio_tell(s->pb);

             memcpy(pkt->data, header, 8);

             ret = avio_read(s->pb, &pkt->data[8], size);

             if (ret < 0) {

                 av_free_packet(pkt);

             } else {

                 packet_read = 1;

                 av_shrink_packet(pkt, ret + 8);
             }

             break;

         case snd__TAG:

             track_number = avio_rl32(pb);

             avio_skip(pb, 4);

             size -= 8;

             if (track_number < fourxm->track_count &&
                 fourxm->tracks[track_number].channels > 0) {
                 ret = av_get_packet(s->pb, pkt, size);
                 if (ret < 0)

                     return AVERROR(EIO);

                 pkt->stream_index =

                     fourxm->tracks[track_number].stream_index;

                 pkt->pts    = fourxm->tracks[track_number].audio_pts;

                 packet_read = 1;

                 /* pts accounting */
                 audio_frame_count = size;

                 if (fourxm->tracks[track_number].adpcm)

                     audio_frame_count -= 2 * (fourxm->tracks[track_number].channels);
                 audio_frame_count /= fourxm->tracks[track_number].channels;
                 if (fourxm->tracks[track_number].adpcm) {

                     audio_frame_count *= 2;

                 } else

                     audio_frame_count /=

                         (fourxm->tracks[track_number].bits / 8);

                 fourxm->tracks[track_number].audio_pts += audio_frame_count;

             } else {

                 avio_skip(pb, size);

             }
             break;
 
         default:

             avio_skip(pb, size);

             break;
         }
     }
     return ret;
 }
 
 static int fourxm_read_close(AVFormatContext *s)
 {

     FourxmDemuxContext *fourxm = s->priv_data;

     av_freep(&fourxm->tracks);

 
     return 0;
 }
 

 AVInputFormat ff_fourxm_demuxer = {

     .name           = "4xm",

     .long_name      = NULL_IF_CONFIG_SMALL("4X Technologies"),

     .priv_data_size = sizeof(FourxmDemuxContext),
     .read_probe     = fourxm_probe,
     .read_header    = fourxm_read_header,
     .read_packet    = fourxm_read_packet,
     .read_close     = fourxm_read_close,

 };