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00023 #include "avcodec.h"
00024 #include "libavutil/intreadwrite.h"
00025 #include "bytestream.h"
00026 #define ALT_BITSTREAM_READER_LE
00027 #include "get_bits.h"
00028
00029 #include "libavutil/lzo.h"
00030
00031 typedef struct XanContext {
00032 AVCodecContext *avctx;
00033 AVFrame pic;
00034
00035 uint8_t *y_buffer;
00036 uint8_t *scratch_buffer;
00037 int buffer_size;
00038 } XanContext;
00039
00040 static av_cold int xan_decode_init(AVCodecContext *avctx)
00041 {
00042 XanContext *s = avctx->priv_data;
00043
00044 s->avctx = avctx;
00045
00046 avctx->pix_fmt = PIX_FMT_YUV420P;
00047
00048 s->buffer_size = avctx->width * avctx->height;
00049 s->y_buffer = av_malloc(s->buffer_size);
00050 if (!s->y_buffer)
00051 return AVERROR(ENOMEM);
00052 s->scratch_buffer = av_malloc(s->buffer_size + 130);
00053 if (!s->scratch_buffer) {
00054 av_freep(&s->y_buffer);
00055 return AVERROR(ENOMEM);
00056 }
00057
00058 return 0;
00059 }
00060
00061 static int xan_unpack_luma(const uint8_t *src, const int src_size,
00062 uint8_t *dst, const int dst_size)
00063 {
00064 int tree_size, eof;
00065 const uint8_t *tree;
00066 int bits, mask;
00067 int tree_root, node;
00068 const uint8_t *dst_end = dst + dst_size;
00069 const uint8_t *src_end = src + src_size;
00070
00071 tree_size = *src++;
00072 eof = *src++;
00073 tree = src - eof * 2 - 2;
00074 tree_root = eof + tree_size;
00075 src += tree_size * 2;
00076
00077 node = tree_root;
00078 bits = *src++;
00079 mask = 0x80;
00080 for (;;) {
00081 int bit = !!(bits & mask);
00082 mask >>= 1;
00083 node = tree[node*2 + bit];
00084 if (node == eof)
00085 break;
00086 if (node < eof) {
00087 *dst++ = node;
00088 if (dst > dst_end)
00089 break;
00090 node = tree_root;
00091 }
00092 if (!mask) {
00093 bits = *src++;
00094 if (src > src_end)
00095 break;
00096 mask = 0x80;
00097 }
00098 }
00099 return dst != dst_end;
00100 }
00101
00102
00103 static int xan_unpack(uint8_t *dest, const int dest_len,
00104 const uint8_t *src, const int src_len)
00105 {
00106 uint8_t opcode;
00107 int size;
00108 uint8_t *orig_dest = dest;
00109 const uint8_t *src_end = src + src_len;
00110 const uint8_t *dest_end = dest + dest_len;
00111
00112 while (dest < dest_end) {
00113 opcode = *src++;
00114
00115 if (opcode < 0xe0) {
00116 int size2, back;
00117 if ((opcode & 0x80) == 0) {
00118 size = opcode & 3;
00119 back = ((opcode & 0x60) << 3) + *src++ + 1;
00120 size2 = ((opcode & 0x1c) >> 2) + 3;
00121 } else if ((opcode & 0x40) == 0) {
00122 size = *src >> 6;
00123 back = (bytestream_get_be16(&src) & 0x3fff) + 1;
00124 size2 = (opcode & 0x3f) + 4;
00125 } else {
00126 size = opcode & 3;
00127 back = ((opcode & 0x10) << 12) + bytestream_get_be16(&src) + 1;
00128 size2 = ((opcode & 0x0c) << 6) + *src++ + 5;
00129 if (size + size2 > dest_end - dest)
00130 break;
00131 }
00132 if (src + size > src_end ||
00133 dest + size + size2 > dest_end ||
00134 dest + size - orig_dest < back )
00135 return -1;
00136 bytestream_get_buffer(&src, dest, size);
00137 dest += size;
00138 av_memcpy_backptr(dest, back, size2);
00139 dest += size2;
00140 } else {
00141 int finish = opcode >= 0xfc;
00142
00143 size = finish ? opcode & 3 : ((opcode & 0x1f) << 2) + 4;
00144 if (src + size > src_end || dest + size > dest_end)
00145 return -1;
00146 bytestream_get_buffer(&src, dest, size);
00147 dest += size;
00148 if (finish)
00149 break;
00150 }
00151 }
00152 return dest - orig_dest;
00153 }
00154
00155 static int xan_decode_chroma(AVCodecContext *avctx, AVPacket *avpkt)
00156 {
00157 const uint8_t *buf = avpkt->data;
00158 XanContext *s = avctx->priv_data;
00159 uint8_t *U, *V;
00160 unsigned chroma_off;
00161 int val, uval, vval;
00162 int i, j;
00163 const uint8_t *src, *src_end;
00164 const uint8_t *table;
00165 int mode, offset, dec_size;
00166
00167 chroma_off = AV_RL32(buf + 4);
00168 if (!chroma_off)
00169 return 0;
00170 if (chroma_off + 10 >= avpkt->size) {
00171 av_log(avctx, AV_LOG_ERROR, "Invalid chroma block position\n");
00172 return -1;
00173 }
00174 src = avpkt->data + 4 + chroma_off;
00175 table = src + 2;
00176 mode = bytestream_get_le16(&src);
00177 offset = bytestream_get_le16(&src) * 2;
00178
00179 if (src - avpkt->data >= avpkt->size - offset) {
00180 av_log(avctx, AV_LOG_ERROR, "Invalid chroma block offset\n");
00181 return -1;
00182 }
00183
00184 memset(s->scratch_buffer, 0, s->buffer_size);
00185 dec_size = xan_unpack(s->scratch_buffer, s->buffer_size, src + offset,
00186 avpkt->size - offset - (src - avpkt->data));
00187 if (dec_size < 0) {
00188 av_log(avctx, AV_LOG_ERROR, "Chroma unpacking failed\n");
00189 return -1;
00190 }
00191
00192 U = s->pic.data[1];
00193 V = s->pic.data[2];
00194 src = s->scratch_buffer;
00195 src_end = src + dec_size;
00196 if (mode) {
00197 for (j = 0; j < avctx->height >> 1; j++) {
00198 for (i = 0; i < avctx->width >> 1; i++) {
00199 if (src_end - src < 1)
00200 return 0;
00201 val = *src++;
00202 if (val) {
00203 val = AV_RL16(table + (val << 1));
00204 uval = (val >> 3) & 0xF8;
00205 vval = (val >> 8) & 0xF8;
00206 U[i] = uval | (uval >> 5);
00207 V[i] = vval | (vval >> 5);
00208 }
00209 }
00210 U += s->pic.linesize[1];
00211 V += s->pic.linesize[2];
00212 }
00213 } else {
00214 uint8_t *U2 = U + s->pic.linesize[1];
00215 uint8_t *V2 = V + s->pic.linesize[2];
00216
00217 for (j = 0; j < avctx->height >> 2; j++) {
00218 for (i = 0; i < avctx->width >> 1; i += 2) {
00219 if (src_end - src < 1)
00220 return 0;
00221 val = *src++;
00222 if (val) {
00223 val = AV_RL16(table + (val << 1));
00224 uval = (val >> 3) & 0xF8;
00225 vval = (val >> 8) & 0xF8;
00226 U[i] = U[i+1] = U2[i] = U2[i+1] = uval | (uval >> 5);
00227 V[i] = V[i+1] = V2[i] = V2[i+1] = vval | (vval >> 5);
00228 }
00229 }
00230 U += s->pic.linesize[1] * 2;
00231 V += s->pic.linesize[2] * 2;
00232 U2 += s->pic.linesize[1] * 2;
00233 V2 += s->pic.linesize[2] * 2;
00234 }
00235 }
00236
00237 return 0;
00238 }
00239
00240 static int xan_decode_frame_type0(AVCodecContext *avctx, AVPacket *avpkt)
00241 {
00242 const uint8_t *buf = avpkt->data;
00243 XanContext *s = avctx->priv_data;
00244 uint8_t *ybuf, *prev_buf, *src = s->scratch_buffer;
00245 unsigned chroma_off, corr_off;
00246 int cur, last, size;
00247 int i, j;
00248 int ret;
00249
00250 corr_off = AV_RL32(buf + 8);
00251 chroma_off = AV_RL32(buf + 4);
00252
00253 if ((ret = xan_decode_chroma(avctx, avpkt)) != 0)
00254 return ret;
00255
00256 size = avpkt->size - 4;
00257 if (corr_off >= avpkt->size) {
00258 av_log(avctx, AV_LOG_WARNING, "Ignoring invalid correction block position\n");
00259 corr_off = 0;
00260 }
00261 if (corr_off)
00262 size = corr_off;
00263 if (chroma_off)
00264 size = FFMIN(size, chroma_off);
00265 ret = xan_unpack_luma(buf + 12, size, src, s->buffer_size >> 1);
00266 if (ret) {
00267 av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
00268 return ret;
00269 }
00270
00271 ybuf = s->y_buffer;
00272 last = *src++;
00273 ybuf[0] = last << 1;
00274 for (j = 1; j < avctx->width - 1; j += 2) {
00275 cur = (last + *src++) & 0x1F;
00276 ybuf[j] = last + cur;
00277 ybuf[j+1] = cur << 1;
00278 last = cur;
00279 }
00280 ybuf[j] = last << 1;
00281 prev_buf = ybuf;
00282 ybuf += avctx->width;
00283
00284 for (i = 1; i < avctx->height; i++) {
00285 last = ((prev_buf[0] >> 1) + *src++) & 0x1F;
00286 ybuf[0] = last << 1;
00287 for (j = 1; j < avctx->width - 1; j += 2) {
00288 cur = ((prev_buf[j + 1] >> 1) + *src++) & 0x1F;
00289 ybuf[j] = last + cur;
00290 ybuf[j+1] = cur << 1;
00291 last = cur;
00292 }
00293 ybuf[j] = last << 1;
00294 prev_buf = ybuf;
00295 ybuf += avctx->width;
00296 }
00297
00298 if (corr_off) {
00299 int corr_end, dec_size;
00300
00301 corr_end = avpkt->size;
00302 if (chroma_off > corr_off)
00303 corr_end = chroma_off;
00304 dec_size = xan_unpack(s->scratch_buffer, s->buffer_size,
00305 avpkt->data + 8 + corr_off,
00306 corr_end - corr_off);
00307 if (dec_size < 0)
00308 dec_size = 0;
00309 else
00310 dec_size = FFMIN(dec_size, s->buffer_size/2 - 1);
00311
00312 for (i = 0; i < dec_size; i++)
00313 s->y_buffer[i*2+1] = (s->y_buffer[i*2+1] + (s->scratch_buffer[i] << 1)) & 0x3F;
00314 }
00315
00316 src = s->y_buffer;
00317 ybuf = s->pic.data[0];
00318 for (j = 0; j < avctx->height; j++) {
00319 for (i = 0; i < avctx->width; i++)
00320 ybuf[i] = (src[i] << 2) | (src[i] >> 3);
00321 src += avctx->width;
00322 ybuf += s->pic.linesize[0];
00323 }
00324
00325 return 0;
00326 }
00327
00328 static int xan_decode_frame_type1(AVCodecContext *avctx, AVPacket *avpkt)
00329 {
00330 const uint8_t *buf = avpkt->data;
00331 XanContext *s = avctx->priv_data;
00332 uint8_t *ybuf, *src = s->scratch_buffer;
00333 int cur, last;
00334 int i, j;
00335 int ret;
00336
00337 if ((ret = xan_decode_chroma(avctx, avpkt)) != 0)
00338 return ret;
00339
00340 ret = xan_unpack_luma(buf + 16, avpkt->size - 16, src,
00341 s->buffer_size >> 1);
00342 if (ret) {
00343 av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
00344 return ret;
00345 }
00346
00347 ybuf = s->y_buffer;
00348 for (i = 0; i < avctx->height; i++) {
00349 last = (ybuf[0] + (*src++ << 1)) & 0x3F;
00350 ybuf[0] = last;
00351 for (j = 1; j < avctx->width - 1; j += 2) {
00352 cur = (ybuf[j + 1] + (*src++ << 1)) & 0x3F;
00353 ybuf[j] = (last + cur) >> 1;
00354 ybuf[j+1] = cur;
00355 last = cur;
00356 }
00357 ybuf[j] = last;
00358 ybuf += avctx->width;
00359 }
00360
00361 src = s->y_buffer;
00362 ybuf = s->pic.data[0];
00363 for (j = 0; j < avctx->height; j++) {
00364 for (i = 0; i < avctx->width; i++)
00365 ybuf[i] = (src[i] << 2) | (src[i] >> 3);
00366 src += avctx->width;
00367 ybuf += s->pic.linesize[0];
00368 }
00369
00370 return 0;
00371 }
00372
00373 static int xan_decode_frame(AVCodecContext *avctx,
00374 void *data, int *data_size,
00375 AVPacket *avpkt)
00376 {
00377 XanContext *s = avctx->priv_data;
00378 int ftype;
00379 int ret;
00380
00381 s->pic.reference = 1;
00382 s->pic.buffer_hints = FF_BUFFER_HINTS_VALID |
00383 FF_BUFFER_HINTS_PRESERVE |
00384 FF_BUFFER_HINTS_REUSABLE;
00385 if ((ret = avctx->reget_buffer(avctx, &s->pic))) {
00386 av_log(s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
00387 return ret;
00388 }
00389
00390 ftype = AV_RL32(avpkt->data);
00391 switch (ftype) {
00392 case 0:
00393 ret = xan_decode_frame_type0(avctx, avpkt);
00394 break;
00395 case 1:
00396 ret = xan_decode_frame_type1(avctx, avpkt);
00397 break;
00398 default:
00399 av_log(avctx, AV_LOG_ERROR, "Unknown frame type %d\n", ftype);
00400 return -1;
00401 }
00402 if (ret)
00403 return ret;
00404
00405 *data_size = sizeof(AVFrame);
00406 *(AVFrame*)data = s->pic;
00407
00408 return avpkt->size;
00409 }
00410
00411 static av_cold int xan_decode_end(AVCodecContext *avctx)
00412 {
00413 XanContext *s = avctx->priv_data;
00414
00415 if (s->pic.data[0])
00416 avctx->release_buffer(avctx, &s->pic);
00417
00418 av_freep(&s->y_buffer);
00419 av_freep(&s->scratch_buffer);
00420
00421 return 0;
00422 }
00423
00424 AVCodec ff_xan_wc4_decoder = {
00425 "xan_wc4",
00426 AVMEDIA_TYPE_VIDEO,
00427 CODEC_ID_XAN_WC4,
00428 sizeof(XanContext),
00429 xan_decode_init,
00430 NULL,
00431 xan_decode_end,
00432 xan_decode_frame,
00433 CODEC_CAP_DR1,
00434 .long_name = NULL_IF_CONFIG_SMALL("Wing Commander IV / Xxan"),
00435 };
00436
