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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 || dest + size + size2 > dest_end)
00133 return -1;
00134 bytestream_get_buffer(&src, dest, size);
00135 dest += size;
00136 av_memcpy_backptr(dest, back, size2);
00137 dest += size2;
00138 } else {
00139 int finish = opcode >= 0xfc;
00140
00141 size = finish ? opcode & 3 : ((opcode & 0x1f) << 2) + 4;
00142 if (src + size > src_end || dest + size > dest_end)
00143 return -1;
00144 bytestream_get_buffer(&src, dest, size);
00145 dest += size;
00146 if (finish)
00147 break;
00148 }
00149 }
00150 return dest - orig_dest;
00151 }
00152
00153 static int xan_decode_chroma(AVCodecContext *avctx, AVPacket *avpkt)
00154 {
00155 const uint8_t *buf = avpkt->data;
00156 XanContext *s = avctx->priv_data;
00157 uint8_t *U, *V;
00158 unsigned chroma_off;
00159 int val, uval, vval;
00160 int i, j;
00161 const uint8_t *src, *src_end;
00162 const uint8_t *table;
00163 int mode, offset, dec_size;
00164
00165 chroma_off = AV_RL32(buf + 4);
00166 if (!chroma_off)
00167 return 0;
00168 if (chroma_off + 10 >= avpkt->size) {
00169 av_log(avctx, AV_LOG_ERROR, "Invalid chroma block position\n");
00170 return -1;
00171 }
00172 src = avpkt->data + 4 + chroma_off;
00173 table = src + 2;
00174 mode = bytestream_get_le16(&src);
00175 offset = bytestream_get_le16(&src) * 2;
00176
00177 if (src - avpkt->data >= avpkt->size - offset) {
00178 av_log(avctx, AV_LOG_ERROR, "Invalid chroma block offset\n");
00179 return -1;
00180 }
00181
00182 memset(s->scratch_buffer, 0, s->buffer_size);
00183 dec_size = xan_unpack(s->scratch_buffer, s->buffer_size, src + offset,
00184 avpkt->size - offset - (src - avpkt->data));
00185 if (dec_size < 0) {
00186 av_log(avctx, AV_LOG_ERROR, "Chroma unpacking failed\n");
00187 return -1;
00188 }
00189
00190 U = s->pic.data[1];
00191 V = s->pic.data[2];
00192 src = s->scratch_buffer;
00193 src_end = src + dec_size;
00194 if (mode) {
00195 for (j = 0; j < avctx->height >> 1; j++) {
00196 for (i = 0; i < avctx->width >> 1; i++) {
00197 val = *src++;
00198 if (val) {
00199 val = AV_RL16(table + (val << 1));
00200 uval = (val >> 3) & 0xF8;
00201 vval = (val >> 8) & 0xF8;
00202 U[i] = uval | (uval >> 5);
00203 V[i] = vval | (vval >> 5);
00204 }
00205 if (src == src_end)
00206 return 0;
00207 }
00208 U += s->pic.linesize[1];
00209 V += s->pic.linesize[2];
00210 }
00211 } else {
00212 uint8_t *U2 = U + s->pic.linesize[1];
00213 uint8_t *V2 = V + s->pic.linesize[2];
00214
00215 for (j = 0; j < avctx->height >> 2; j++) {
00216 for (i = 0; i < avctx->width >> 1; i += 2) {
00217 val = *src++;
00218 if (val) {
00219 val = AV_RL16(table + (val << 1));
00220 uval = (val >> 3) & 0xF8;
00221 vval = (val >> 8) & 0xF8;
00222 U[i] = U[i+1] = U2[i] = U2[i+1] = uval | (uval >> 5);
00223 V[i] = V[i+1] = V2[i] = V2[i+1] = vval | (vval >> 5);
00224 }
00225 }
00226 U += s->pic.linesize[1] * 2;
00227 V += s->pic.linesize[2] * 2;
00228 U2 += s->pic.linesize[1] * 2;
00229 V2 += s->pic.linesize[2] * 2;
00230 }
00231 }
00232
00233 return 0;
00234 }
00235
00236 static int xan_decode_frame_type0(AVCodecContext *avctx, AVPacket *avpkt)
00237 {
00238 const uint8_t *buf = avpkt->data;
00239 XanContext *s = avctx->priv_data;
00240 uint8_t *ybuf, *prev_buf, *src = s->scratch_buffer;
00241 unsigned chroma_off, corr_off;
00242 int cur, last, size;
00243 int i, j;
00244 int ret;
00245
00246 corr_off = AV_RL32(buf + 8);
00247 chroma_off = AV_RL32(buf + 4);
00248
00249 if ((ret = xan_decode_chroma(avctx, avpkt)) != 0)
00250 return ret;
00251
00252 size = avpkt->size - 4;
00253 if (corr_off >= avpkt->size) {
00254 av_log(avctx, AV_LOG_WARNING, "Ignoring invalid correction block position\n");
00255 corr_off = 0;
00256 }
00257 if (corr_off)
00258 size = corr_off;
00259 if (chroma_off)
00260 size = FFMIN(size, chroma_off);
00261 ret = xan_unpack_luma(buf + 12, size, src, s->buffer_size >> 1);
00262 if (ret) {
00263 av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
00264 return ret;
00265 }
00266
00267 ybuf = s->y_buffer;
00268 last = *src++;
00269 ybuf[0] = last << 1;
00270 for (j = 1; j < avctx->width - 1; j += 2) {
00271 cur = (last + *src++) & 0x1F;
00272 ybuf[j] = last + cur;
00273 ybuf[j+1] = cur << 1;
00274 last = cur;
00275 }
00276 ybuf[j] = last << 1;
00277 prev_buf = ybuf;
00278 ybuf += avctx->width;
00279
00280 for (i = 1; i < avctx->height; i++) {
00281 last = ((prev_buf[0] >> 1) + *src++) & 0x1F;
00282 ybuf[0] = last << 1;
00283 for (j = 1; j < avctx->width - 1; j += 2) {
00284 cur = ((prev_buf[j + 1] >> 1) + *src++) & 0x1F;
00285 ybuf[j] = last + cur;
00286 ybuf[j+1] = cur << 1;
00287 last = cur;
00288 }
00289 ybuf[j] = last << 1;
00290 prev_buf = ybuf;
00291 ybuf += avctx->width;
00292 }
00293
00294 if (corr_off) {
00295 int corr_end, dec_size;
00296
00297 corr_end = avpkt->size;
00298 if (chroma_off > corr_off)
00299 corr_end = chroma_off;
00300 dec_size = xan_unpack(s->scratch_buffer, s->buffer_size,
00301 avpkt->data + 8 + corr_off,
00302 corr_end - corr_off);
00303 if (dec_size < 0)
00304 dec_size = 0;
00305 for (i = 0; i < dec_size; i++)
00306 s->y_buffer[i*2+1] = (s->y_buffer[i*2+1] + (s->scratch_buffer[i] << 1)) & 0x3F;
00307 }
00308
00309 src = s->y_buffer;
00310 ybuf = s->pic.data[0];
00311 for (j = 0; j < avctx->height; j++) {
00312 for (i = 0; i < avctx->width; i++)
00313 ybuf[i] = (src[i] << 2) | (src[i] >> 3);
00314 src += avctx->width;
00315 ybuf += s->pic.linesize[0];
00316 }
00317
00318 return 0;
00319 }
00320
00321 static int xan_decode_frame_type1(AVCodecContext *avctx, AVPacket *avpkt)
00322 {
00323 const uint8_t *buf = avpkt->data;
00324 XanContext *s = avctx->priv_data;
00325 uint8_t *ybuf, *src = s->scratch_buffer;
00326 int cur, last;
00327 int i, j;
00328 int ret;
00329
00330 if ((ret = xan_decode_chroma(avctx, avpkt)) != 0)
00331 return ret;
00332
00333 ret = xan_unpack_luma(buf + 16, avpkt->size - 16, src,
00334 s->buffer_size >> 1);
00335 if (ret) {
00336 av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
00337 return ret;
00338 }
00339
00340 ybuf = s->y_buffer;
00341 for (i = 0; i < avctx->height; i++) {
00342 last = (ybuf[0] + (*src++ << 1)) & 0x3F;
00343 ybuf[0] = last;
00344 for (j = 1; j < avctx->width - 1; j += 2) {
00345 cur = (ybuf[j + 1] + (*src++ << 1)) & 0x3F;
00346 ybuf[j] = (last + cur) >> 1;
00347 ybuf[j+1] = cur;
00348 last = cur;
00349 }
00350 ybuf[j] = last;
00351 ybuf += avctx->width;
00352 }
00353
00354 src = s->y_buffer;
00355 ybuf = s->pic.data[0];
00356 for (j = 0; j < avctx->height; j++) {
00357 for (i = 0; i < avctx->width; i++)
00358 ybuf[i] = (src[i] << 2) | (src[i] >> 3);
00359 src += avctx->width;
00360 ybuf += s->pic.linesize[0];
00361 }
00362
00363 return 0;
00364 }
00365
00366 static int xan_decode_frame(AVCodecContext *avctx,
00367 void *data, int *data_size,
00368 AVPacket *avpkt)
00369 {
00370 XanContext *s = avctx->priv_data;
00371 int ftype;
00372 int ret;
00373
00374 s->pic.reference = 1;
00375 s->pic.buffer_hints = FF_BUFFER_HINTS_VALID |
00376 FF_BUFFER_HINTS_PRESERVE |
00377 FF_BUFFER_HINTS_REUSABLE;
00378 if ((ret = avctx->reget_buffer(avctx, &s->pic))) {
00379 av_log(s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
00380 return ret;
00381 }
00382
00383 ftype = AV_RL32(avpkt->data);
00384 switch (ftype) {
00385 case 0:
00386 ret = xan_decode_frame_type0(avctx, avpkt);
00387 break;
00388 case 1:
00389 ret = xan_decode_frame_type1(avctx, avpkt);
00390 break;
00391 default:
00392 av_log(avctx, AV_LOG_ERROR, "Unknown frame type %d\n", ftype);
00393 return -1;
00394 }
00395 if (ret)
00396 return ret;
00397
00398 *data_size = sizeof(AVFrame);
00399 *(AVFrame*)data = s->pic;
00400
00401 return avpkt->size;
00402 }
00403
00404 static av_cold int xan_decode_end(AVCodecContext *avctx)
00405 {
00406 XanContext *s = avctx->priv_data;
00407
00408 if (s->pic.data[0])
00409 avctx->release_buffer(avctx, &s->pic);
00410
00411 av_freep(&s->y_buffer);
00412 av_freep(&s->scratch_buffer);
00413
00414 return 0;
00415 }
00416
00417 AVCodec ff_xan_wc4_decoder = {
00418 "xan_wc4",
00419 AVMEDIA_TYPE_VIDEO,
00420 CODEC_ID_XAN_WC4,
00421 sizeof(XanContext),
00422 xan_decode_init,
00423 NULL,
00424 xan_decode_end,
00425 xan_decode_frame,
00426 CODEC_CAP_DR1,
00427 .long_name = NULL_IF_CONFIG_SMALL("Wing Commander IV / Xxan"),
00428 };
00429