libavformat/wc3movie.c - vendor/opensource/ffmpeg - Git at Google

 /*
  * Wing Commander III Movie (.mve) File Demuxer
  * 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 libavformat/wc3movie.c
  * Wing Commander III Movie file demuxer
  * by Mike Melanson (melanson@pcisys.net)
  * for more information on the WC3 .mve file format, visit:
  *   http://www.pcisys.net/~melanson/codecs/
  */

 #include "libavutil/intreadwrite.h"
 #include "avformat.h"

 #define WC3_PREAMBLE_SIZE 8

 #define FORM_TAG MKTAG('F', 'O', 'R', 'M')
 #define MOVE_TAG MKTAG('M', 'O', 'V', 'E')
 #define  PC__TAG MKTAG('_', 'P', 'C', '_')
 #define SOND_TAG MKTAG('S', 'O', 'N', 'D')
 #define BNAM_TAG MKTAG('B', 'N', 'A', 'M')
 #define SIZE_TAG MKTAG('S', 'I', 'Z', 'E')
 #define PALT_TAG MKTAG('P', 'A', 'L', 'T')
 #define INDX_TAG MKTAG('I', 'N', 'D', 'X')
 #define BRCH_TAG MKTAG('B', 'R', 'C', 'H')
 #define SHOT_TAG MKTAG('S', 'H', 'O', 'T')
 #define VGA__TAG MKTAG('V', 'G', 'A', ' ')
 #define TEXT_TAG MKTAG('T', 'E', 'X', 'T')
 #define AUDI_TAG MKTAG('A', 'U', 'D', 'I')

 /* video resolution unless otherwise specified */
 #define WC3_DEFAULT_WIDTH 320
 #define WC3_DEFAULT_HEIGHT 165

 /* always use the same PCM audio parameters */
 #define WC3_SAMPLE_RATE 22050
 #define WC3_AUDIO_CHANNELS 1
 #define WC3_AUDIO_BITS 16

 /* nice, constant framerate */
 #define WC3_FRAME_FPS 15

 #define PALETTE_SIZE (256 * 3)
 #define PALETTE_COUNT 256

 typedef struct Wc3DemuxContext {
     int width;
     int height;
     unsigned char *palettes;
     int palette_count;
     int64_t pts;
     int video_stream_index;
     int audio_stream_index;

     AVPaletteControl palette_control;

 } Wc3DemuxContext;

 /* bizarre palette lookup table */
 static const unsigned char wc3_pal_lookup[] = {
   0x00, 0x03, 0x05, 0x07, 0x09, 0x0B, 0x0D, 0x0E,
   0x10, 0x12, 0x13, 0x15, 0x16, 0x18, 0x19, 0x1A,
   0x1C, 0x1D, 0x1F, 0x20, 0x21, 0x23, 0x24, 0x25,
   0x27, 0x28, 0x29, 0x2A, 0x2C, 0x2D, 0x2E, 0x2F,
   0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x38, 0x39,
   0x3A, 0x3B, 0x3C, 0x3D, 0x3F, 0x40, 0x41, 0x42,
   0x43, 0x44, 0x45, 0x46, 0x48, 0x49, 0x4A, 0x4B,
   0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53,
   0x54, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B, 0x5C,
   0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64,
   0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C,
   0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74,
   0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C,
   0x7D, 0x7D, 0x7E, 0x7F, 0x80, 0x81, 0x82, 0x83,
   0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B,
   0x8C, 0x8D, 0x8D, 0x8E, 0x8F, 0x90, 0x91, 0x92,
   0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x99,
   0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F, 0xA0, 0xA1,
   0xA2, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8,
   0xA9, 0xAA, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF,
   0xB0, 0xB1, 0xB2, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6,
   0xB7, 0xB8, 0xB9, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD,
   0xBE, 0xBF, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4,
   0xC5, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xCB,
   0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD0, 0xD1,
   0xD2, 0xD3, 0xD4, 0xD5, 0xD5, 0xD6, 0xD7, 0xD8,
   0xD9, 0xDA, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF,
   0xDF, 0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE4, 0xE5,
   0xE6, 0xE7, 0xE8, 0xE9, 0xE9, 0xEA, 0xEB, 0xEC,
   0xED, 0xED, 0xEE, 0xEF, 0xF0, 0xF1, 0xF1, 0xF2,
   0xF3, 0xF4, 0xF5, 0xF6, 0xF6, 0xF7, 0xF8, 0xF9,
   0xFA, 0xFA, 0xFB, 0xFC, 0xFD, 0xFD, 0xFD, 0xFD
 };


 static int wc3_probe(AVProbeData *p)
 {
     if (p->buf_size < 12)
         return 0;

     if ((AV_RL32(&p->buf[0]) != FORM_TAG) ||
         (AV_RL32(&p->buf[8]) != MOVE_TAG))
         return 0;

     return AVPROBE_SCORE_MAX;
 }

 static int wc3_read_header(AVFormatContext *s,
                            AVFormatParameters *ap)
 {
     Wc3DemuxContext *wc3 = s->priv_data;
     ByteIOContext *pb = s->pb;
     unsigned int fourcc_tag;
     unsigned int size;
     AVStream *st;
     unsigned char preamble[WC3_PREAMBLE_SIZE];
     char buffer[513];
     int ret = 0;
     int current_palette = 0;
     int bytes_to_read;
     int i;
     unsigned char rotate;

     /* default context members */
     wc3->width = WC3_DEFAULT_WIDTH;
     wc3->height = WC3_DEFAULT_HEIGHT;
     wc3->palettes = NULL;
     wc3->palette_count = 0;
     wc3->pts = 0;
     wc3->video_stream_index = wc3->audio_stream_index = 0;

     /* skip the first 3 32-bit numbers */
     url_fseek(pb, 12, SEEK_CUR);

     /* traverse through the chunks and load the header information before
      * the first BRCH tag */
     if ((ret = get_buffer(pb, preamble, WC3_PREAMBLE_SIZE)) !=
         WC3_PREAMBLE_SIZE)
         return AVERROR(EIO);
     fourcc_tag = AV_RL32(&preamble[0]);
     size = (AV_RB32(&preamble[4]) + 1) & (~1);

     do {
         switch (fourcc_tag) {

         case SOND_TAG:
         case INDX_TAG:
             /* SOND unknown, INDX unnecessary; ignore both */
             url_fseek(pb, size, SEEK_CUR);
             break;

         case PC__TAG:
             /* need the number of palettes */
             url_fseek(pb, 8, SEEK_CUR);
             if ((ret = get_buffer(pb, preamble, 4)) != 4)
                 return AVERROR(EIO);
             wc3->palette_count = AV_RL32(&preamble[0]);
             if((unsigned)wc3->palette_count >= UINT_MAX / PALETTE_SIZE){
                 wc3->palette_count= 0;
                 return -1;
             }
             wc3->palettes = av_malloc(wc3->palette_count * PALETTE_SIZE);
             break;

         case BNAM_TAG:
             /* load up the name */
             if ((unsigned)size < 512)
                 bytes_to_read = size;
             else
                 bytes_to_read = 512;
             if ((ret = get_buffer(pb, buffer, bytes_to_read)) != bytes_to_read)
                 return AVERROR(EIO);
             buffer[bytes_to_read] = 0;
             av_metadata_set(&s->metadata, "title", buffer);
             break;

         case SIZE_TAG:
             /* video resolution override */
             if ((ret = get_buffer(pb, preamble, WC3_PREAMBLE_SIZE)) !=
                 WC3_PREAMBLE_SIZE)
                 return AVERROR(EIO);
             wc3->width = AV_RL32(&preamble[0]);
             wc3->height = AV_RL32(&preamble[4]);
             break;

         case PALT_TAG:
             /* one of several palettes */
             if ((unsigned)current_palette >= wc3->palette_count)
                 return AVERROR_INVALIDDATA;
             if ((ret = get_buffer(pb,
                 &wc3->palettes[current_palette * PALETTE_SIZE],
                 PALETTE_SIZE)) != PALETTE_SIZE)
                 return AVERROR(EIO);

             /* transform the current palette in place */
             for (i = current_palette * PALETTE_SIZE;
                  i < (current_palette + 1) * PALETTE_SIZE; i++) {
                 /* rotate each palette component left by 2 and use the result
                  * as an index into the color component table */
                 rotate = ((wc3->palettes[i] << 2) & 0xFF) |
                          ((wc3->palettes[i] >> 6) & 0xFF);
                 wc3->palettes[i] = wc3_pal_lookup[rotate];
             }
             current_palette++;
             break;

         default:
             av_log(s, AV_LOG_ERROR, "  unrecognized WC3 chunk: %c%c%c%c (0x%02X%02X%02X%02X)\n",
                 preamble[0], preamble[1], preamble[2], preamble[3],
                 preamble[0], preamble[1], preamble[2], preamble[3]);
             return AVERROR_INVALIDDATA;
             break;
         }

         if ((ret = get_buffer(pb, preamble, WC3_PREAMBLE_SIZE)) !=
             WC3_PREAMBLE_SIZE)
             return AVERROR(EIO);
         fourcc_tag = AV_RL32(&preamble[0]);
         /* chunk sizes are 16-bit aligned */
         size = (AV_RB32(&preamble[4]) + 1) & (~1);

     } while (fourcc_tag != BRCH_TAG);

     /* initialize the decoder streams */
     st = av_new_stream(s, 0);
     if (!st)
         return AVERROR(ENOMEM);
     av_set_pts_info(st, 33, 1, WC3_FRAME_FPS);
     wc3->video_stream_index = st->index;
     st->codec->codec_type = CODEC_TYPE_VIDEO;
     st->codec->codec_id = CODEC_ID_XAN_WC3;
     st->codec->codec_tag = 0;  /* no fourcc */
     st->codec->width = wc3->width;
     st->codec->height = wc3->height;

     /* palette considerations */
     st->codec->palctrl = &wc3->palette_control;

     st = av_new_stream(s, 0);
     if (!st)
         return AVERROR(ENOMEM);
     av_set_pts_info(st, 33, 1, WC3_FRAME_FPS);
     wc3->audio_stream_index = st->index;
     st->codec->codec_type = CODEC_TYPE_AUDIO;
     st->codec->codec_id = CODEC_ID_PCM_S16LE;
     st->codec->codec_tag = 1;
     st->codec->channels = WC3_AUDIO_CHANNELS;
     st->codec->bits_per_coded_sample = WC3_AUDIO_BITS;
     st->codec->sample_rate = WC3_SAMPLE_RATE;
     st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *
         st->codec->bits_per_coded_sample;
     st->codec->block_align = WC3_AUDIO_BITS * WC3_AUDIO_CHANNELS;

     return 0;
 }

 static int wc3_read_packet(AVFormatContext *s,
                            AVPacket *pkt)
 {
     Wc3DemuxContext *wc3 = s->priv_data;
     ByteIOContext *pb = s->pb;
     unsigned int fourcc_tag;
     unsigned int size;
     int packet_read = 0;
     int ret = 0;
     unsigned char preamble[WC3_PREAMBLE_SIZE];
     unsigned char text[1024];
     unsigned int palette_number;
     int i;
     unsigned char r, g, b;
     int base_palette_index;

     while (!packet_read) {

         /* get the next chunk preamble */
         if ((ret = get_buffer(pb, preamble, WC3_PREAMBLE_SIZE)) !=
             WC3_PREAMBLE_SIZE)
             ret = AVERROR(EIO);

         fourcc_tag = AV_RL32(&preamble[0]);
         /* chunk sizes are 16-bit aligned */
         size = (AV_RB32(&preamble[4]) + 1) & (~1);

         switch (fourcc_tag) {

         case BRCH_TAG:
             /* no-op */
             break;

         case SHOT_TAG:
             /* load up new palette */
             if ((ret = get_buffer(pb, preamble, 4)) != 4)
                 return AVERROR(EIO);
             palette_number = AV_RL32(&preamble[0]);
             if (palette_number >= wc3->palette_count)
                 return AVERROR_INVALIDDATA;
             base_palette_index = palette_number * PALETTE_COUNT * 3;
             for (i = 0; i < PALETTE_COUNT; i++) {
                 r = wc3->palettes[base_palette_index + i * 3 + 0];
                 g = wc3->palettes[base_palette_index + i * 3 + 1];
                 b = wc3->palettes[base_palette_index + i * 3 + 2];
                 wc3->palette_control.palette[i] = (r << 16) | (g << 8) | (b);
             }
             wc3->palette_control.palette_changed = 1;
             break;

         case VGA__TAG:
             /* send out video chunk */
             ret= av_get_packet(pb, pkt, size);
             pkt->stream_index = wc3->video_stream_index;
             pkt->pts = wc3->pts;
             if (ret != size)
                 ret = AVERROR(EIO);
             packet_read = 1;
             break;

         case TEXT_TAG:
             /* subtitle chunk */
 #if 0
             url_fseek(pb, size, SEEK_CUR);
 #else
             if ((unsigned)size > sizeof(text) || (ret = get_buffer(pb, text, size)) != size)
                 ret = AVERROR(EIO);
             else {
                 int i = 0;
                 av_log (s, AV_LOG_DEBUG, "Subtitle time!\n");
                 av_log (s, AV_LOG_DEBUG, "  inglish: %s\n", &text[i + 1]);
                 i += text[i] + 1;
                 av_log (s, AV_LOG_DEBUG, "  doytsch: %s\n", &text[i + 1]);
                 i += text[i] + 1;
                 av_log (s, AV_LOG_DEBUG, "  fronsay: %s\n", &text[i + 1]);
             }
 #endif
             break;

         case AUDI_TAG:
             /* send out audio chunk */
             ret= av_get_packet(pb, pkt, size);
             pkt->stream_index = wc3->audio_stream_index;
             pkt->pts = wc3->pts;
             if (ret != size)
                 ret = AVERROR(EIO);

             /* time to advance pts */
             wc3->pts++;

             packet_read = 1;
             break;

         default:
             av_log (s, AV_LOG_ERROR, "  unrecognized WC3 chunk: %c%c%c%c (0x%02X%02X%02X%02X)\n",
                 preamble[0], preamble[1], preamble[2], preamble[3],
                 preamble[0], preamble[1], preamble[2], preamble[3]);
             ret = AVERROR_INVALIDDATA;
             packet_read = 1;
             break;
         }
     }

     return ret;
 }

 static int wc3_read_close(AVFormatContext *s)
 {
     Wc3DemuxContext *wc3 = s->priv_data;

     av_free(wc3->palettes);

     return 0;
 }

 AVInputFormat wc3_demuxer = {
     "wc3movie",
     NULL_IF_CONFIG_SMALL("Wing Commander III movie format"),
     sizeof(Wc3DemuxContext),
     wc3_probe,
     wc3_read_header,
     wc3_read_packet,
     wc3_read_close,
 };
	/*
	* Wing Commander III Movie (.mve) File Demuxer
	* 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 libavformat/wc3movie.c
	* Wing Commander III Movie file demuxer
	* by Mike Melanson (melanson@pcisys.net)
	* for more information on the WC3 .mve file format, visit:
	* http://www.pcisys.net/~melanson/codecs/
	*/

	#include "libavutil/intreadwrite.h"
	#include "avformat.h"

	#define WC3_PREAMBLE_SIZE 8

	#define FORM_TAG MKTAG('F', 'O', 'R', 'M')
	#define MOVE_TAG MKTAG('M', 'O', 'V', 'E')
	#define PC__TAG MKTAG('_', 'P', 'C', '_')
	#define SOND_TAG MKTAG('S', 'O', 'N', 'D')
	#define BNAM_TAG MKTAG('B', 'N', 'A', 'M')
	#define SIZE_TAG MKTAG('S', 'I', 'Z', 'E')
	#define PALT_TAG MKTAG('P', 'A', 'L', 'T')
	#define INDX_TAG MKTAG('I', 'N', 'D', 'X')
	#define BRCH_TAG MKTAG('B', 'R', 'C', 'H')
	#define SHOT_TAG MKTAG('S', 'H', 'O', 'T')
	#define VGA__TAG MKTAG('V', 'G', 'A', ' ')
	#define TEXT_TAG MKTAG('T', 'E', 'X', 'T')
	#define AUDI_TAG MKTAG('A', 'U', 'D', 'I')

	/* video resolution unless otherwise specified */
	#define WC3_DEFAULT_WIDTH 320
	#define WC3_DEFAULT_HEIGHT 165

	/* always use the same PCM audio parameters */
	#define WC3_SAMPLE_RATE 22050
	#define WC3_AUDIO_CHANNELS 1
	#define WC3_AUDIO_BITS 16

	/* nice, constant framerate */
	#define WC3_FRAME_FPS 15

	#define PALETTE_SIZE (256 * 3)
	#define PALETTE_COUNT 256

	typedef struct Wc3DemuxContext {
	int width;
	int height;
	unsigned char *palettes;
	int palette_count;
	int64_t pts;
	int video_stream_index;
	int audio_stream_index;

	AVPaletteControl palette_control;

	} Wc3DemuxContext;

	/* bizarre palette lookup table */
	static const unsigned char wc3_pal_lookup[] = {
	0x00, 0x03, 0x05, 0x07, 0x09, 0x0B, 0x0D, 0x0E,
	0x10, 0x12, 0x13, 0x15, 0x16, 0x18, 0x19, 0x1A,
	0x1C, 0x1D, 0x1F, 0x20, 0x21, 0x23, 0x24, 0x25,
	0x27, 0x28, 0x29, 0x2A, 0x2C, 0x2D, 0x2E, 0x2F,
	0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x38, 0x39,
	0x3A, 0x3B, 0x3C, 0x3D, 0x3F, 0x40, 0x41, 0x42,
	0x43, 0x44, 0x45, 0x46, 0x48, 0x49, 0x4A, 0x4B,
	0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53,
	0x54, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B, 0x5C,
	0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64,
	0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C,
	0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74,
	0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C,
	0x7D, 0x7D, 0x7E, 0x7F, 0x80, 0x81, 0x82, 0x83,
	0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B,
	0x8C, 0x8D, 0x8D, 0x8E, 0x8F, 0x90, 0x91, 0x92,
	0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x99,
	0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F, 0xA0, 0xA1,
	0xA2, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8,
	0xA9, 0xAA, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF,
	0xB0, 0xB1, 0xB2, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6,
	0xB7, 0xB8, 0xB9, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD,
	0xBE, 0xBF, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4,
	0xC5, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xCB,
	0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD0, 0xD1,
	0xD2, 0xD3, 0xD4, 0xD5, 0xD5, 0xD6, 0xD7, 0xD8,
	0xD9, 0xDA, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF,
	0xDF, 0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE4, 0xE5,
	0xE6, 0xE7, 0xE8, 0xE9, 0xE9, 0xEA, 0xEB, 0xEC,
	0xED, 0xED, 0xEE, 0xEF, 0xF0, 0xF1, 0xF1, 0xF2,
	0xF3, 0xF4, 0xF5, 0xF6, 0xF6, 0xF7, 0xF8, 0xF9,
	0xFA, 0xFA, 0xFB, 0xFC, 0xFD, 0xFD, 0xFD, 0xFD
	};


	static int wc3_probe(AVProbeData *p)
	{
	if (p->buf_size < 12)
	return 0;

	if ((AV_RL32(&p->buf[0]) != FORM_TAG) \|\|
	(AV_RL32(&p->buf[8]) != MOVE_TAG))
	return 0;

	return AVPROBE_SCORE_MAX;
	}

	static int wc3_read_header(AVFormatContext *s,
	AVFormatParameters *ap)
	{
	Wc3DemuxContext *wc3 = s->priv_data;
	ByteIOContext *pb = s->pb;
	unsigned int fourcc_tag;
	unsigned int size;
	AVStream *st;
	unsigned char preamble[WC3_PREAMBLE_SIZE];
	char buffer[513];
	int ret = 0;
	int current_palette = 0;
	int bytes_to_read;
	int i;
	unsigned char rotate;

	/* default context members */
	wc3->width = WC3_DEFAULT_WIDTH;
	wc3->height = WC3_DEFAULT_HEIGHT;
	wc3->palettes = NULL;
	wc3->palette_count = 0;
	wc3->pts = 0;
	wc3->video_stream_index = wc3->audio_stream_index = 0;

	/* skip the first 3 32-bit numbers */
	url_fseek(pb, 12, SEEK_CUR);

	/* traverse through the chunks and load the header information before
	* the first BRCH tag */
	if ((ret = get_buffer(pb, preamble, WC3_PREAMBLE_SIZE)) !=
	WC3_PREAMBLE_SIZE)
	return AVERROR(EIO);
	fourcc_tag = AV_RL32(&preamble[0]);
	size = (AV_RB32(&preamble[4]) + 1) & (~1);

	do {
	switch (fourcc_tag) {

	case SOND_TAG:
	case INDX_TAG:
	/* SOND unknown, INDX unnecessary; ignore both */
	url_fseek(pb, size, SEEK_CUR);
	break;

	case PC__TAG:
	/* need the number of palettes */
	url_fseek(pb, 8, SEEK_CUR);
	if ((ret = get_buffer(pb, preamble, 4)) != 4)
	return AVERROR(EIO);
	wc3->palette_count = AV_RL32(&preamble[0]);
	if((unsigned)wc3->palette_count >= UINT_MAX / PALETTE_SIZE){
	wc3->palette_count= 0;
	return -1;
	}
	wc3->palettes = av_malloc(wc3->palette_count * PALETTE_SIZE);
	break;

	case BNAM_TAG:
	/* load up the name */
	if ((unsigned)size < 512)
	bytes_to_read = size;
	else
	bytes_to_read = 512;
	if ((ret = get_buffer(pb, buffer, bytes_to_read)) != bytes_to_read)
	return AVERROR(EIO);
	buffer[bytes_to_read] = 0;
	av_metadata_set(&s->metadata, "title", buffer);
	break;

	case SIZE_TAG:
	/* video resolution override */
	if ((ret = get_buffer(pb, preamble, WC3_PREAMBLE_SIZE)) !=
	WC3_PREAMBLE_SIZE)
	return AVERROR(EIO);
	wc3->width = AV_RL32(&preamble[0]);
	wc3->height = AV_RL32(&preamble[4]);
	break;

	case PALT_TAG:
	/* one of several palettes */
	if ((unsigned)current_palette >= wc3->palette_count)
	return AVERROR_INVALIDDATA;
	if ((ret = get_buffer(pb,
	&wc3->palettes[current_palette * PALETTE_SIZE],
	PALETTE_SIZE)) != PALETTE_SIZE)
	return AVERROR(EIO);

	/* transform the current palette in place */
	for (i = current_palette * PALETTE_SIZE;
	i < (current_palette + 1) * PALETTE_SIZE; i++) {
	/* rotate each palette component left by 2 and use the result
	* as an index into the color component table */
	rotate = ((wc3->palettes[i] << 2) & 0xFF) \|
	((wc3->palettes[i] >> 6) & 0xFF);
	wc3->palettes[i] = wc3_pal_lookup[rotate];
	}
	current_palette++;
	break;

	default:
	av_log(s, AV_LOG_ERROR, " unrecognized WC3 chunk: %c%c%c%c (0x%02X%02X%02X%02X)\n",
	preamble[0], preamble[1], preamble[2], preamble[3],
	preamble[0], preamble[1], preamble[2], preamble[3]);
	return AVERROR_INVALIDDATA;
	break;
	}

	if ((ret = get_buffer(pb, preamble, WC3_PREAMBLE_SIZE)) !=
	WC3_PREAMBLE_SIZE)
	return AVERROR(EIO);
	fourcc_tag = AV_RL32(&preamble[0]);
	/* chunk sizes are 16-bit aligned */
	size = (AV_RB32(&preamble[4]) + 1) & (~1);

	} while (fourcc_tag != BRCH_TAG);

	/* initialize the decoder streams */
	st = av_new_stream(s, 0);
	if (!st)
	return AVERROR(ENOMEM);
	av_set_pts_info(st, 33, 1, WC3_FRAME_FPS);
	wc3->video_stream_index = st->index;
	st->codec->codec_type = CODEC_TYPE_VIDEO;
	st->codec->codec_id = CODEC_ID_XAN_WC3;
	st->codec->codec_tag = 0; /* no fourcc */
	st->codec->width = wc3->width;
	st->codec->height = wc3->height;

	/* palette considerations */
	st->codec->palctrl = &wc3->palette_control;

	st = av_new_stream(s, 0);
	if (!st)
	return AVERROR(ENOMEM);
	av_set_pts_info(st, 33, 1, WC3_FRAME_FPS);
	wc3->audio_stream_index = st->index;
	st->codec->codec_type = CODEC_TYPE_AUDIO;
	st->codec->codec_id = CODEC_ID_PCM_S16LE;
	st->codec->codec_tag = 1;
	st->codec->channels = WC3_AUDIO_CHANNELS;
	st->codec->bits_per_coded_sample = WC3_AUDIO_BITS;
	st->codec->sample_rate = WC3_SAMPLE_RATE;
	st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *
	st->codec->bits_per_coded_sample;
	st->codec->block_align = WC3_AUDIO_BITS * WC3_AUDIO_CHANNELS;

	return 0;
	}

	static int wc3_read_packet(AVFormatContext *s,
	AVPacket *pkt)
	{
	Wc3DemuxContext *wc3 = s->priv_data;
	ByteIOContext *pb = s->pb;
	unsigned int fourcc_tag;
	unsigned int size;
	int packet_read = 0;
	int ret = 0;
	unsigned char preamble[WC3_PREAMBLE_SIZE];
	unsigned char text[1024];
	unsigned int palette_number;
	int i;
	unsigned char r, g, b;
	int base_palette_index;

	while (!packet_read) {

	/* get the next chunk preamble */
	if ((ret = get_buffer(pb, preamble, WC3_PREAMBLE_SIZE)) !=
	WC3_PREAMBLE_SIZE)
	ret = AVERROR(EIO);

	fourcc_tag = AV_RL32(&preamble[0]);
	/* chunk sizes are 16-bit aligned */
	size = (AV_RB32(&preamble[4]) + 1) & (~1);

	switch (fourcc_tag) {

	case BRCH_TAG:
	/* no-op */
	break;

	case SHOT_TAG:
	/* load up new palette */
	if ((ret = get_buffer(pb, preamble, 4)) != 4)
	return AVERROR(EIO);
	palette_number = AV_RL32(&preamble[0]);
	if (palette_number >= wc3->palette_count)
	return AVERROR_INVALIDDATA;
	base_palette_index = palette_number * PALETTE_COUNT * 3;
	for (i = 0; i < PALETTE_COUNT; i++) {
	r = wc3->palettes[base_palette_index + i * 3 + 0];
	g = wc3->palettes[base_palette_index + i * 3 + 1];
	b = wc3->palettes[base_palette_index + i * 3 + 2];
	wc3->palette_control.palette[i] = (r << 16) \| (g << 8) \| (b);
	}
	wc3->palette_control.palette_changed = 1;
	break;

	case VGA__TAG:
	/* send out video chunk */
	ret= av_get_packet(pb, pkt, size);
	pkt->stream_index = wc3->video_stream_index;
	pkt->pts = wc3->pts;
	if (ret != size)
	ret = AVERROR(EIO);
	packet_read = 1;
	break;

	case TEXT_TAG:
	/* subtitle chunk */
	#if 0
	url_fseek(pb, size, SEEK_CUR);
	#else
	if ((unsigned)size > sizeof(text) \|\| (ret = get_buffer(pb, text, size)) != size)
	ret = AVERROR(EIO);
	else {
	int i = 0;
	av_log (s, AV_LOG_DEBUG, "Subtitle time!\n");
	av_log (s, AV_LOG_DEBUG, " inglish: %s\n", &text[i + 1]);
	i += text[i] + 1;
	av_log (s, AV_LOG_DEBUG, " doytsch: %s\n", &text[i + 1]);
	i += text[i] + 1;
	av_log (s, AV_LOG_DEBUG, " fronsay: %s\n", &text[i + 1]);
	}
	#endif
	break;

	case AUDI_TAG:
	/* send out audio chunk */
	ret= av_get_packet(pb, pkt, size);
	pkt->stream_index = wc3->audio_stream_index;
	pkt->pts = wc3->pts;
	if (ret != size)
	ret = AVERROR(EIO);

	/* time to advance pts */
	wc3->pts++;

	packet_read = 1;
	break;

	default:
	av_log (s, AV_LOG_ERROR, " unrecognized WC3 chunk: %c%c%c%c (0x%02X%02X%02X%02X)\n",
	preamble[0], preamble[1], preamble[2], preamble[3],
	preamble[0], preamble[1], preamble[2], preamble[3]);
	ret = AVERROR_INVALIDDATA;
	packet_read = 1;
	break;
	}
	}

	return ret;
	}

	static int wc3_read_close(AVFormatContext *s)
	{
	Wc3DemuxContext *wc3 = s->priv_data;

	av_free(wc3->palettes);

	return 0;
	}

	AVInputFormat wc3_demuxer = {
	"wc3movie",
	NULL_IF_CONFIG_SMALL("Wing Commander III movie format"),
	sizeof(Wc3DemuxContext),
	wc3_probe,
	wc3_read_header,
	wc3_read_packet,
	wc3_read_close,
	};