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00023 #include "avcodec.h"
00024 #include "libavutil/intreadwrite.h"
00025 #include "bytestream.h"
00026 #define 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 GetByteContext gb;
00039 } XanContext;
00040
00041 static av_cold int xan_decode_init(AVCodecContext *avctx)
00042 {
00043 XanContext *s = avctx->priv_data;
00044
00045 s->avctx = avctx;
00046
00047 avctx->pix_fmt = PIX_FMT_YUV420P;
00048
00049 if (avctx->width & 1) {
00050 av_log(avctx, AV_LOG_ERROR, "Invalid frame width: %d.\n", avctx->width);
00051 return AVERROR(EINVAL);
00052 }
00053
00054 s->buffer_size = avctx->width * avctx->height;
00055 s->y_buffer = av_malloc(s->buffer_size);
00056 if (!s->y_buffer)
00057 return AVERROR(ENOMEM);
00058 s->scratch_buffer = av_malloc(s->buffer_size + 130);
00059 if (!s->scratch_buffer) {
00060 av_freep(&s->y_buffer);
00061 return AVERROR(ENOMEM);
00062 }
00063
00064 return 0;
00065 }
00066
00067 static int xan_unpack_luma(XanContext *s,
00068 uint8_t *dst, const int dst_size)
00069 {
00070 int tree_size, eof;
00071 int bits, mask;
00072 int tree_root, node;
00073 const uint8_t *dst_end = dst + dst_size;
00074 GetByteContext tree = s->gb;
00075 int start_off = bytestream2_tell(&tree);
00076
00077 tree_size = bytestream2_get_byte(&s->gb);
00078 eof = bytestream2_get_byte(&s->gb);
00079 tree_root = eof + tree_size;
00080 bytestream2_skip(&s->gb, tree_size * 2);
00081
00082 node = tree_root;
00083 bits = bytestream2_get_byte(&s->gb);
00084 mask = 0x80;
00085 for (;;) {
00086 int bit = !!(bits & mask);
00087 mask >>= 1;
00088 bytestream2_seek(&tree, start_off + node*2 + bit - eof * 2, SEEK_SET);
00089 node = bytestream2_get_byte(&tree);
00090 if (node == eof)
00091 break;
00092 if (node < eof) {
00093 *dst++ = node;
00094 if (dst > dst_end)
00095 break;
00096 node = tree_root;
00097 }
00098 if (!mask) {
00099 if (bytestream2_get_bytes_left(&s->gb) <= 0)
00100 break;
00101 bits = bytestream2_get_byteu(&s->gb);
00102 mask = 0x80;
00103 }
00104 }
00105 return dst != dst_end ? AVERROR_INVALIDDATA : 0;
00106 }
00107
00108
00109 static int xan_unpack(XanContext *s,
00110 uint8_t *dest, const int dest_len)
00111 {
00112 uint8_t opcode;
00113 int size;
00114 uint8_t *orig_dest = dest;
00115 const uint8_t *dest_end = dest + dest_len;
00116
00117 while (dest < dest_end) {
00118 if (bytestream2_get_bytes_left(&s->gb) <= 0)
00119 return AVERROR_INVALIDDATA;
00120
00121 opcode = bytestream2_get_byteu(&s->gb);
00122
00123 if (opcode < 0xe0) {
00124 int size2, back;
00125 if ((opcode & 0x80) == 0) {
00126 size = opcode & 3;
00127 back = ((opcode & 0x60) << 3) + bytestream2_get_byte(&s->gb) + 1;
00128 size2 = ((opcode & 0x1c) >> 2) + 3;
00129 } else if ((opcode & 0x40) == 0) {
00130 size = bytestream2_peek_byte(&s->gb) >> 6;
00131 back = (bytestream2_get_be16(&s->gb) & 0x3fff) + 1;
00132 size2 = (opcode & 0x3f) + 4;
00133 } else {
00134 size = opcode & 3;
00135 back = ((opcode & 0x10) << 12) + bytestream2_get_be16(&s->gb) + 1;
00136 size2 = ((opcode & 0x0c) << 6) + bytestream2_get_byte(&s->gb) + 5;
00137 if (size + size2 > dest_end - dest)
00138 break;
00139 }
00140 if (dest + size + size2 > dest_end ||
00141 dest - orig_dest + size < back)
00142 return -1;
00143 bytestream2_get_buffer(&s->gb, dest, size);
00144 dest += size;
00145 av_memcpy_backptr(dest, back, size2);
00146 dest += size2;
00147 } else {
00148 int finish = opcode >= 0xfc;
00149
00150 size = finish ? opcode & 3 : ((opcode & 0x1f) << 2) + 4;
00151 if (dest_end - dest < size)
00152 return -1;
00153 bytestream2_get_buffer(&s->gb, dest, size);
00154 dest += size;
00155 if (finish)
00156 break;
00157 }
00158 }
00159 return dest - orig_dest;
00160 }
00161
00162 static int xan_decode_chroma(AVCodecContext *avctx, unsigned chroma_off)
00163 {
00164 XanContext *s = avctx->priv_data;
00165 uint8_t *U, *V;
00166 int val, uval, vval;
00167 int i, j;
00168 const uint8_t *src, *src_end;
00169 const uint8_t *table;
00170 int mode, offset, dec_size, table_size;
00171
00172 if (!chroma_off)
00173 return 0;
00174 if (chroma_off + 4 >= bytestream2_get_bytes_left(&s->gb)) {
00175 av_log(avctx, AV_LOG_ERROR, "Invalid chroma block position\n");
00176 return -1;
00177 }
00178 bytestream2_seek(&s->gb, chroma_off + 4, SEEK_SET);
00179 mode = bytestream2_get_le16(&s->gb);
00180 table = s->gb.buffer;
00181 table_size = bytestream2_get_le16(&s->gb);
00182 offset = table_size * 2;
00183 table_size += 1;
00184
00185 if (offset >= bytestream2_get_bytes_left(&s->gb)) {
00186 av_log(avctx, AV_LOG_ERROR, "Invalid chroma block offset\n");
00187 return -1;
00188 }
00189
00190 bytestream2_skip(&s->gb, offset);
00191 memset(s->scratch_buffer, 0, s->buffer_size);
00192 dec_size = xan_unpack(s, s->scratch_buffer, s->buffer_size);
00193 if (dec_size < 0) {
00194 av_log(avctx, AV_LOG_ERROR, "Chroma unpacking failed\n");
00195 return -1;
00196 }
00197
00198 U = s->pic.data[1];
00199 V = s->pic.data[2];
00200 src = s->scratch_buffer;
00201 src_end = src + dec_size;
00202 if (mode) {
00203 for (j = 0; j < avctx->height >> 1; j++) {
00204 for (i = 0; i < avctx->width >> 1; i++) {
00205 val = *src++;
00206 if (val && val < table_size) {
00207 val = AV_RL16(table + (val << 1));
00208 uval = (val >> 3) & 0xF8;
00209 vval = (val >> 8) & 0xF8;
00210 U[i] = uval | (uval >> 5);
00211 V[i] = vval | (vval >> 5);
00212 }
00213 if (src == src_end)
00214 return 0;
00215 }
00216 U += s->pic.linesize[1];
00217 V += s->pic.linesize[2];
00218 }
00219 } else {
00220 uint8_t *U2 = U + s->pic.linesize[1];
00221 uint8_t *V2 = V + s->pic.linesize[2];
00222
00223 for (j = 0; j < avctx->height >> 2; j++) {
00224 for (i = 0; i < avctx->width >> 1; i += 2) {
00225 val = *src++;
00226 if (val && val < table_size) {
00227 val = AV_RL16(table + (val << 1));
00228 uval = (val >> 3) & 0xF8;
00229 vval = (val >> 8) & 0xF8;
00230 U[i] = U[i+1] = U2[i] = U2[i+1] = uval | (uval >> 5);
00231 V[i] = V[i+1] = V2[i] = V2[i+1] = vval | (vval >> 5);
00232 }
00233 }
00234 U += s->pic.linesize[1] * 2;
00235 V += s->pic.linesize[2] * 2;
00236 U2 += s->pic.linesize[1] * 2;
00237 V2 += s->pic.linesize[2] * 2;
00238 }
00239 }
00240
00241 return 0;
00242 }
00243
00244 static int xan_decode_frame_type0(AVCodecContext *avctx)
00245 {
00246 XanContext *s = avctx->priv_data;
00247 uint8_t *ybuf, *prev_buf, *src = s->scratch_buffer;
00248 unsigned chroma_off, corr_off;
00249 int cur, last;
00250 int i, j;
00251 int ret;
00252
00253 chroma_off = bytestream2_get_le32(&s->gb);
00254 corr_off = bytestream2_get_le32(&s->gb);
00255
00256 if ((ret = xan_decode_chroma(avctx, chroma_off)) != 0)
00257 return ret;
00258
00259 if (corr_off >= (s->gb.buffer_end - s->gb.buffer_start)) {
00260 av_log(avctx, AV_LOG_WARNING, "Ignoring invalid correction block position\n");
00261 corr_off = 0;
00262 }
00263 bytestream2_seek(&s->gb, 12, SEEK_SET);
00264 ret = xan_unpack_luma(s, src, s->buffer_size >> 1);
00265 if (ret) {
00266 av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
00267 return ret;
00268 }
00269
00270 ybuf = s->y_buffer;
00271 last = *src++;
00272 ybuf[0] = last << 1;
00273 for (j = 1; j < avctx->width - 1; j += 2) {
00274 cur = (last + *src++) & 0x1F;
00275 ybuf[j] = last + cur;
00276 ybuf[j+1] = cur << 1;
00277 last = cur;
00278 }
00279 ybuf[j] = last << 1;
00280 prev_buf = ybuf;
00281 ybuf += avctx->width;
00282
00283 for (i = 1; i < avctx->height; i++) {
00284 last = ((prev_buf[0] >> 1) + *src++) & 0x1F;
00285 ybuf[0] = last << 1;
00286 for (j = 1; j < avctx->width - 1; j += 2) {
00287 cur = ((prev_buf[j + 1] >> 1) + *src++) & 0x1F;
00288 ybuf[j] = last + cur;
00289 ybuf[j+1] = cur << 1;
00290 last = cur;
00291 }
00292 ybuf[j] = last << 1;
00293 prev_buf = ybuf;
00294 ybuf += avctx->width;
00295 }
00296
00297 if (corr_off) {
00298 int corr_end, dec_size;
00299
00300 corr_end = (s->gb.buffer_end - s->gb.buffer_start);
00301 if (chroma_off > corr_off)
00302 corr_end = chroma_off;
00303 bytestream2_seek(&s->gb, 8 + corr_off, SEEK_SET);
00304 dec_size = xan_unpack(s, s->scratch_buffer, s->buffer_size / 2);
00305 if (dec_size < 0)
00306 dec_size = 0;
00307 for (i = 0; i < dec_size; i++)
00308 s->y_buffer[i*2+1] = (s->y_buffer[i*2+1] + (s->scratch_buffer[i] << 1)) & 0x3F;
00309 }
00310
00311 src = s->y_buffer;
00312 ybuf = s->pic.data[0];
00313 for (j = 0; j < avctx->height; j++) {
00314 for (i = 0; i < avctx->width; i++)
00315 ybuf[i] = (src[i] << 2) | (src[i] >> 3);
00316 src += avctx->width;
00317 ybuf += s->pic.linesize[0];
00318 }
00319
00320 return 0;
00321 }
00322
00323 static int xan_decode_frame_type1(AVCodecContext *avctx)
00324 {
00325 XanContext *s = avctx->priv_data;
00326 uint8_t *ybuf, *src = s->scratch_buffer;
00327 int cur, last;
00328 int i, j;
00329 int ret;
00330
00331 if ((ret = xan_decode_chroma(avctx, bytestream2_get_le32(&s->gb))) != 0)
00332 return ret;
00333
00334 bytestream2_seek(&s->gb, 16, SEEK_SET);
00335 ret = xan_unpack_luma(s, src,
00336 s->buffer_size >> 1);
00337 if (ret) {
00338 av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
00339 return ret;
00340 }
00341
00342 ybuf = s->y_buffer;
00343 for (i = 0; i < avctx->height; i++) {
00344 last = (ybuf[0] + (*src++ << 1)) & 0x3F;
00345 ybuf[0] = last;
00346 for (j = 1; j < avctx->width - 1; j += 2) {
00347 cur = (ybuf[j + 1] + (*src++ << 1)) & 0x3F;
00348 ybuf[j] = (last + cur) >> 1;
00349 ybuf[j+1] = cur;
00350 last = cur;
00351 }
00352 ybuf[j] = last;
00353 ybuf += avctx->width;
00354 }
00355
00356 src = s->y_buffer;
00357 ybuf = s->pic.data[0];
00358 for (j = 0; j < avctx->height; j++) {
00359 for (i = 0; i < avctx->width; i++)
00360 ybuf[i] = (src[i] << 2) | (src[i] >> 3);
00361 src += avctx->width;
00362 ybuf += s->pic.linesize[0];
00363 }
00364
00365 return 0;
00366 }
00367
00368 static int xan_decode_frame(AVCodecContext *avctx,
00369 void *data, int *data_size,
00370 AVPacket *avpkt)
00371 {
00372 XanContext *s = avctx->priv_data;
00373 int ftype;
00374 int ret;
00375
00376 s->pic.reference = 1;
00377 s->pic.buffer_hints = FF_BUFFER_HINTS_VALID |
00378 FF_BUFFER_HINTS_PRESERVE |
00379 FF_BUFFER_HINTS_REUSABLE;
00380 if ((ret = avctx->reget_buffer(avctx, &s->pic))) {
00381 av_log(s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
00382 return ret;
00383 }
00384
00385 bytestream2_init(&s->gb, avpkt->data, avpkt->size);
00386 ftype = bytestream2_get_le32(&s->gb);
00387 switch (ftype) {
00388 case 0:
00389 ret = xan_decode_frame_type0(avctx);
00390 break;
00391 case 1:
00392 ret = xan_decode_frame_type1(avctx);
00393 break;
00394 default:
00395 av_log(avctx, AV_LOG_ERROR, "Unknown frame type %d\n", ftype);
00396 return -1;
00397 }
00398 if (ret)
00399 return ret;
00400
00401 *data_size = sizeof(AVFrame);
00402 *(AVFrame*)data = s->pic;
00403
00404 return avpkt->size;
00405 }
00406
00407 static av_cold int xan_decode_end(AVCodecContext *avctx)
00408 {
00409 XanContext *s = avctx->priv_data;
00410
00411 if (s->pic.data[0])
00412 avctx->release_buffer(avctx, &s->pic);
00413
00414 av_freep(&s->y_buffer);
00415 av_freep(&s->scratch_buffer);
00416
00417 return 0;
00418 }
00419
00420 AVCodec ff_xan_wc4_decoder = {
00421 .name = "xan_wc4",
00422 .type = AVMEDIA_TYPE_VIDEO,
00423 .id = CODEC_ID_XAN_WC4,
00424 .priv_data_size = sizeof(XanContext),
00425 .init = xan_decode_init,
00426 .close = xan_decode_end,
00427 .decode = xan_decode_frame,
00428 .capabilities = CODEC_CAP_DR1,
00429 .long_name = NULL_IF_CONFIG_SMALL("Wing Commander IV / Xxan"),
00430 };
00431