/* * Wing Commander/Xan Video Decoder * Copyright (C) 2003 the ffmpeg project * * This library 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 of the License, or (at your option) any later version. * * This library 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 this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */ /** * @file xan.c * Xan video decoder for Wing Commander III & IV computer games * by Mario Brito (mbrito@student.dei.uc.pt) * and Mike Melanson (melanson@pcisys.net) * * The xan_wc3 decoder outputs the following colorspaces natively: * PAL8 (default), RGB555, RGB565, RGB24, BGR24, RGBA32, YUV444P */ #include #include #include #include #include "common.h" #include "avcodec.h" #include "dsputil.h" #define PALETTE_COUNT 256 #define PALETTE_CONTROL_SIZE ((256 * 3) + 1) typedef struct XanContext { AVCodecContext *avctx; DSPContext dsp; AVFrame last_frame; AVFrame current_frame; unsigned char *buf; int size; unsigned char palette[PALETTE_COUNT * 4]; /* scratch space */ unsigned char *buffer1; unsigned char *buffer2; } XanContext; /* RGB -> YUV conversion stuff */ #define SCALEFACTOR 65536 #define CENTERSAMPLE 128 #define COMPUTE_Y(r, g, b) \ (unsigned char) \ ((y_r_table[r] + y_g_table[g] + y_b_table[b]) / SCALEFACTOR) #define COMPUTE_U(r, g, b) \ (unsigned char) \ ((u_r_table[r] + u_g_table[g] + u_b_table[b]) / SCALEFACTOR + CENTERSAMPLE) #define COMPUTE_V(r, g, b) \ (unsigned char) \ ((v_r_table[r] + v_g_table[g] + v_b_table[b]) / SCALEFACTOR + CENTERSAMPLE) #define Y_R (SCALEFACTOR * 0.29900) #define Y_G (SCALEFACTOR * 0.58700) #define Y_B (SCALEFACTOR * 0.11400) #define U_R (SCALEFACTOR * -0.16874) #define U_G (SCALEFACTOR * -0.33126) #define U_B (SCALEFACTOR * 0.50000) #define V_R (SCALEFACTOR * 0.50000) #define V_G (SCALEFACTOR * -0.41869) #define V_B (SCALEFACTOR * -0.08131) /* * Precalculate all of the YUV tables since it requires fewer than * 10 kilobytes to store them. */ static int y_r_table[256]; static int y_g_table[256]; static int y_b_table[256]; static int u_r_table[256]; static int u_g_table[256]; static int u_b_table[256]; static int v_r_table[256]; static int v_g_table[256]; static int v_b_table[256]; static int xan_decode_init(AVCodecContext *avctx) { XanContext *s = avctx->priv_data; int i; s->avctx = avctx; if ((avctx->codec->id == CODEC_ID_XAN_WC3) && (s->avctx->palctrl == NULL)) { av_log(avctx, AV_LOG_ERROR, " WC3 Xan video: palette expected.\n"); return -1; } avctx->pix_fmt = PIX_FMT_PAL8; avctx->has_b_frames = 0; dsputil_init(&s->dsp, avctx); /* initialize the RGB -> YUV tables */ for (i = 0; i < 256; i++) { y_r_table[i] = Y_R * i; y_g_table[i] = Y_G * i; y_b_table[i] = Y_B * i; u_r_table[i] = U_R * i; u_g_table[i] = U_G * i; u_b_table[i] = U_B * i; v_r_table[i] = V_R * i; v_g_table[i] = V_G * i; v_b_table[i] = V_B * i; } s->buffer1 = av_malloc(avctx->width * avctx->height); s->buffer2 = av_malloc(avctx->width * avctx->height); if (!s->buffer1 || !s->buffer2) return -1; return 0; } /* This function is used in lieu of memcpy(). This decoder can not use * memcpy because the memory locations often overlap and * memcpy doesn't like that; it's not uncommon, for example, for * dest = src+1, to turn byte A into pattern AAAAAAAA. * This was originally repz movsb in Intel x86 ASM. */ static inline void bytecopy(unsigned char *dest, unsigned char *src, int count) { int i; for (i = 0; i < count; i++) dest[i] = src[i]; } static int xan_huffman_decode(unsigned char *dest, unsigned char *src) { unsigned char byte = *src++; unsigned char ival = byte + 0x16; unsigned char * ptr = src + byte*2; unsigned char val = ival; int counter = 0; unsigned char bits = *ptr++; while ( val != 0x16 ) { if ( (1 << counter) & bits ) val = src[byte + val - 0x17]; else val = src[val - 0x17]; if ( val < 0x16 ) { *dest++ = val; val = ival; } if (counter++ == 7) { counter = 0; bits = *ptr++; } } return 0; } static void xan_unpack(unsigned char *dest, unsigned char *src) { unsigned char opcode; int size; int offset; int byte1, byte2, byte3; for (;;) { opcode = *src++; if ( (opcode & 0x80) == 0 ) { offset = *src++; size = opcode & 3; bytecopy(dest, src, size); dest += size; src += size; size = ((opcode & 0x1c) >> 2) + 3; bytecopy (dest, dest - (((opcode & 0x60) << 3) + offset + 1), size); dest += size; } else if ( (opcode & 0x40) == 0 ) { byte1 = *src++; byte2 = *src++; size = byte1 >> 6; bytecopy (dest, src, size); dest += size; src += size; size = (opcode & 0x3f) + 4; bytecopy (dest, dest - (((byte1 & 0x3f) << 8) + byte2 + 1), size); dest += size; } else if ( (opcode & 0x20) == 0 ) { byte1 = *src++; byte2 = *src++; byte3 = *src++; size = opcode & 3; bytecopy (dest, src, size); dest += size; src += size; size = byte3 + 5 + ((opcode & 0xc) << 6); bytecopy (dest, dest - ((((opcode & 0x10) >> 4) << 0x10) + 1 + (byte1 << 8) + byte2), size); dest += size; } else { size = ((opcode & 0x1f) << 2) + 4; if (size > 0x70) break; bytecopy (dest, src, size); dest += size; src += size; } } size = opcode & 3; bytecopy(dest, src, size); dest += size; src += size; } static void inline xan_wc3_build_palette(XanContext *s, unsigned int *palette_data) { int i; unsigned char r, g, b; unsigned short *palette16; unsigned int *palette32; unsigned int pal_elem; /* transform the palette passed through the palette control structure * into the necessary internal format depending on colorspace */ switch (s->avctx->pix_fmt) { case PIX_FMT_RGB555: palette16 = (unsigned short *)s->palette; for (i = 0; i < PALETTE_COUNT; i++) { pal_elem = palette_data[i]; r = (pal_elem >> 16) & 0xff; g = (pal_elem >> 8) & 0xff; b = pal_elem & 0xff; palette16[i] = ((r >> 3) << 10) | ((g >> 3) << 5) | ((b >> 3) << 0); } break; case PIX_FMT_RGB565: palette16 = (unsigned short *)s->palette; for (i = 0; i < PALETTE_COUNT; i++) { pal_elem = palette_data[i]; r = (pal_elem >> 16) & 0xff; g = (pal_elem >> 8) & 0xff; b = pal_elem & 0xff; palette16[i] = ((r >> 3) << 11) | ((g >> 2) << 5) | ((b >> 3) << 0); } break; case PIX_FMT_RGB24: for (i = 0; i < PALETTE_COUNT; i++) { pal_elem = palette_data[i]; r = (pal_elem >> 16) & 0xff; g = (pal_elem >> 8) & 0xff; b = pal_elem & 0xff; s->palette[i * 4 + 0] = r; s->palette[i * 4 + 1] = g; s->palette[i * 4 + 2] = b; } break; case PIX_FMT_BGR24: for (i = 0; i < PALETTE_COUNT; i++) { pal_elem = palette_data[i]; r = (pal_elem >> 16) & 0xff; g = (pal_elem >> 8) & 0xff; b = pal_elem & 0xff; s->palette[i * 4 + 0] = b; s->palette[i * 4 + 1] = g; s->palette[i * 4 + 2] = r; } break; case PIX_FMT_PAL8: case PIX_FMT_RGBA32: palette32 = (unsigned int *)s->palette; memcpy (palette32, palette_data, PALETTE_COUNT * sizeof(unsigned int)); break; case PIX_FMT_YUV444P: for (i = 0; i < PALETTE_COUNT; i++) { pal_elem = palette_data[i]; r = (pal_elem >> 16) & 0xff; g = (pal_elem >> 8) & 0xff; b = pal_elem & 0xff; s->palette[i * 4 + 0] = COMPUTE_Y(r, g, b); s->palette[i * 4 + 1] = COMPUTE_U(r, g, b); s->palette[i * 4 + 2] = COMPUTE_V(r, g, b); } break; default: av_log(s->avctx, AV_LOG_ERROR, " Xan WC3: Unhandled colorspace\n"); break; } } /* advance current_x variable; reset accounting variables if current_x * moves beyond width */ #define ADVANCE_CURRENT_X() \ current_x++; \ if (current_x >= width) { \ index += line_inc; \ current_x = 0; \ } static void inline xan_wc3_output_pixel_run(XanContext *s, unsigned char *pixel_buffer, int x, int y, int pixel_count) { int stride; int line_inc; int index; int current_x; int width = s->avctx->width; unsigned char pix; unsigned char *palette_plane; unsigned char *y_plane; unsigned char *u_plane; unsigned char *v_plane; unsigned char *rgb_plane; unsigned short *rgb16_plane; unsigned short *palette16; unsigned int *rgb32_plane; unsigned int *palette32; switch (s->avctx->pix_fmt) { case PIX_FMT_PAL8: palette_plane = s->current_frame.data[0]; stride = s->current_frame.linesize[0]; line_inc = stride - width; index = y * stride + x; current_x = x; while(pixel_count--) { /* don't do a memcpy() here; keyframes generally copy an entire * frame of data and the stride needs to be accounted for */ palette_plane[index++] = *pixel_buffer++; ADVANCE_CURRENT_X(); } break; case PIX_FMT_RGB555: case PIX_FMT_RGB565: rgb16_plane = (unsigned short *)s->current_frame.data[0]; palette16 = (unsigned short *)s->palette; stride = s->current_frame.linesize[0] / 2; line_inc = stride - width; index = y * stride + x; current_x = x; while(pixel_count--) { rgb16_plane[index++] = palette16[*pixel_buffer++]; ADVANCE_CURRENT_X(); } break; case PIX_FMT_RGB24: case PIX_FMT_BGR24: rgb_plane = s->current_frame.data[0]; stride = s->current_frame.linesize[0]; line_inc = stride - width * 3; index = y * stride + x * 3; current_x = x; while(pixel_count--) { pix = *pixel_buffer++; rgb_plane[index++] = s->palette[pix * 4 + 0]; rgb_plane[index++] = s->palette[pix * 4 + 1]; rgb_plane[index++] = s->palette[pix * 4 + 2]; ADVANCE_CURRENT_X(); } break; case PIX_FMT_RGBA32: rgb32_plane = (unsigned int *)s->current_frame.data[0]; palette32 = (unsigned int *)s->palette; stride = s->current_frame.linesize[0] / 4; line_inc = stride - width; index = y * stride + x; current_x = x; while(pixel_count--) { rgb32_plane[index++] = palette32[*pixel_buffer++]; ADVANCE_CURRENT_X(); } break; case PIX_FMT_YUV444P: y_plane = s->current_frame.data[0]; u_plane = s->current_frame.data[1]; v_plane = s->current_frame.data[2]; stride = s->current_frame.linesize[0]; line_inc = stride - width; index = y * stride + x; current_x = x; while(pixel_count--) { pix = *pixel_buffer++; y_plane[index] = s->palette[pix * 4 + 0]; u_plane[index] = s->palette[pix * 4 + 1]; v_plane[index] = s->palette[pix * 4 + 2]; index++; ADVANCE_CURRENT_X(); } break; default: av_log(s->avctx, AV_LOG_ERROR, " Xan WC3: Unhandled colorspace\n"); break; } } #define ADVANCE_CURFRAME_X() \ curframe_x++; \ if (curframe_x >= width) { \ curframe_index += line_inc; \ curframe_x = 0; \ } #define ADVANCE_PREVFRAME_X() \ prevframe_x++; \ if (prevframe_x >= width) { \ prevframe_index += line_inc; \ prevframe_x = 0; \ } static void inline xan_wc3_copy_pixel_run(XanContext *s, int x, int y, int pixel_count, int motion_x, int motion_y) { int stride; int line_inc; int curframe_index, prevframe_index; int curframe_x, prevframe_x; int width = s->avctx->width; unsigned char *palette_plane, *prev_palette_plane; unsigned char *y_plane, *u_plane, *v_plane; unsigned char *prev_y_plane, *prev_u_plane, *prev_v_plane; unsigned char *rgb_plane, *prev_rgb_plane; unsigned short *rgb16_plane, *prev_rgb16_plane; unsigned int *rgb32_plane, *prev_rgb32_plane; switch (s->avctx->pix_fmt) { case PIX_FMT_PAL8: palette_plane = s->current_frame.data[0]; prev_palette_plane = s->last_frame.data[0]; stride = s->current_frame.linesize[0]; line_inc = stride - width; curframe_index = y * stride + x; curframe_x = x; prevframe_index = (y + motion_y) * stride + x + motion_x; prevframe_x = x + motion_x; while(pixel_count--) { palette_plane[curframe_index++] = prev_palette_plane[prevframe_index++]; ADVANCE_CURFRAME_X(); ADVANCE_PREVFRAME_X(); } break; case PIX_FMT_RGB555: case PIX_FMT_RGB565: rgb16_plane = (unsigned short *)s->current_frame.data[0]; prev_rgb16_plane = (unsigned short *)s->last_frame.data[0]; stride = s->current_frame.linesize[0] / 2; line_inc = stride - width; curframe_index = y * stride + x; curframe_x = x; prevframe_index = (y + motion_y) * stride + x + motion_x; prevframe_x = x + motion_x; while(pixel_count--) { rgb16_plane[curframe_index++] = prev_rgb16_plane[prevframe_index++]; ADVANCE_CURFRAME_X(); ADVANCE_PREVFRAME_X(); } break; case PIX_FMT_RGB24: case PIX_FMT_BGR24: rgb_plane = s->current_frame.data[0]; prev_rgb_plane = s->last_frame.data[0]; stride = s->current_frame.linesize[0]; line_inc = stride - width * 3; curframe_index = y * stride + x * 3; curframe_x = x; prevframe_index = (y + motion_y) * stride + (3 * (x + motion_x)); prevframe_x = x + motion_x; while(pixel_count--) { rgb_plane[curframe_index++] = prev_rgb_plane[prevframe_index++]; rgb_plane[curframe_index++] = prev_rgb_plane[prevframe_index++]; rgb_plane[curframe_index++] = prev_rgb_plane[prevframe_index++]; ADVANCE_CURFRAME_X(); ADVANCE_PREVFRAME_X(); } break; case PIX_FMT_RGBA32: rgb32_plane = (unsigned int *)s->current_frame.data[0]; prev_rgb32_plane = (unsigned int *)s->last_frame.data[0]; stride = s->current_frame.linesize[0] / 4; line_inc = stride - width; curframe_index = y * stride + x; curframe_x = x; prevframe_index = (y + motion_y) * stride + x + motion_x; prevframe_x = x + motion_x; while(pixel_count--) { rgb32_plane[curframe_index++] = prev_rgb32_plane[prevframe_index++]; ADVANCE_CURFRAME_X(); ADVANCE_PREVFRAME_X(); } break; case PIX_FMT_YUV444P: y_plane = s->current_frame.data[0]; u_plane = s->current_frame.data[1]; v_plane = s->current_frame.data[2]; prev_y_plane = s->last_frame.data[0]; prev_u_plane = s->last_frame.data[1]; prev_v_plane = s->last_frame.data[2]; stride = s->current_frame.linesize[0]; line_inc = stride - width; curframe_index = y * stride + x; curframe_x = x; prevframe_index = (y + motion_y) * stride + x + motion_x; prevframe_x = x + motion_x; while(pixel_count--) { y_plane[curframe_index] = prev_y_plane[prevframe_index]; u_plane[curframe_index] = prev_u_plane[prevframe_index]; v_plane[curframe_index] = prev_v_plane[prevframe_index]; curframe_index++; ADVANCE_CURFRAME_X(); prevframe_index++; ADVANCE_PREVFRAME_X(); } break; default: av_log(s->avctx, AV_LOG_ERROR, " Xan WC3: Unhandled colorspace\n"); break; } } static void xan_wc3_decode_frame(XanContext *s) { int width = s->avctx->width; int height = s->avctx->height; int total_pixels = width * height; unsigned char opcode; unsigned char flag = 0; int size = 0; int motion_x, motion_y; int x, y; unsigned char *opcode_buffer = s->buffer1; unsigned char *imagedata_buffer = s->buffer2; /* pointers to segments inside the compressed chunk */ unsigned char *huffman_segment; unsigned char *size_segment; unsigned char *vector_segment; unsigned char *imagedata_segment; huffman_segment = s->buf + LE_16(&s->buf[0]); size_segment = s->buf + LE_16(&s->buf[2]); vector_segment = s->buf + LE_16(&s->buf[4]); imagedata_segment = s->buf + LE_16(&s->buf[6]); xan_huffman_decode(opcode_buffer, huffman_segment); if (imagedata_segment[0] == 2) xan_unpack(imagedata_buffer, &imagedata_segment[1]); else imagedata_buffer = &imagedata_segment[1]; /* use the decoded data segments to build the frame */ x = y = 0; while (total_pixels) { opcode = *opcode_buffer++; size = 0; switch (opcode) { case 0: flag ^= 1; continue; case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8: size = opcode; break; case 12: case 13: case 14: case 15: case 16: case 17: case 18: size += (opcode - 10); break; case 9: case 19: size = *size_segment++; break; case 10: case 20: size = BE_16(&size_segment[0]); size_segment += 2; break; case 11: case 21: size = (size_segment[0] << 16) | (size_segment[1] << 8) | size_segment[2]; size_segment += 3; break; } if (opcode < 12) { flag ^= 1; if (flag) { /* run of (size) pixels is unchanged from last frame */ xan_wc3_copy_pixel_run(s, x, y, size, 0, 0); } else { /* output a run of pixels from imagedata_buffer */ xan_wc3_output_pixel_run(s, imagedata_buffer, x, y, size); imagedata_buffer += size; } } else { /* run-based motion compensation from last frame */ motion_x = (*vector_segment >> 4) & 0xF; motion_y = *vector_segment & 0xF; vector_segment++; /* sign extension */ if (motion_x & 0x8) motion_x |= 0xFFFFFFF0; if (motion_y & 0x8) motion_y |= 0xFFFFFFF0; /* copy a run of pixels from the previous frame */ xan_wc3_copy_pixel_run(s, x, y, size, motion_x, motion_y); flag = 0; } /* coordinate accounting */ total_pixels -= size; while (size) { if (x + size >= width) { y++; size -= (width - x); x = 0; } else { x += size; size = 0; } } } /* for PAL8, make the palette available on the way out */ if (s->avctx->pix_fmt == PIX_FMT_PAL8) { memcpy(s->current_frame.data[1], s->palette, PALETTE_COUNT * 4); s->current_frame.palette_has_changed = 1; s->avctx->palctrl->palette_changed = 0; } } static void xan_wc4_decode_frame(XanContext *s) { } static int xan_decode_frame(AVCodecContext *avctx, void *data, int *data_size, uint8_t *buf, int buf_size) { XanContext *s = avctx->priv_data; AVPaletteControl *palette_control = avctx->palctrl; int keyframe = 0; if (palette_control->palette_changed) { /* load the new palette and reset the palette control */ xan_wc3_build_palette(s, palette_control->palette); /* If pal8 we clear flag when we copy palette */ if (s->avctx->pix_fmt != PIX_FMT_PAL8) palette_control->palette_changed = 0; keyframe = 1; } if (avctx->get_buffer(avctx, &s->current_frame)) { av_log(s->avctx, AV_LOG_ERROR, " Xan Video: get_buffer() failed\n"); return -1; } s->current_frame.reference = 3; s->buf = buf; s->size = buf_size; if (avctx->codec->id == CODEC_ID_XAN_WC3) xan_wc3_decode_frame(s); else if (avctx->codec->id == CODEC_ID_XAN_WC4) xan_wc4_decode_frame(s); /* release the last frame if it is allocated */ if (s->last_frame.data[0]) avctx->release_buffer(avctx, &s->last_frame); /* shuffle frames */ s->last_frame = s->current_frame; *data_size = sizeof(AVFrame); *(AVFrame*)data = s->current_frame; /* always report that the buffer was completely consumed */ return buf_size; } static int xan_decode_end(AVCodecContext *avctx) { XanContext *s = avctx->priv_data; /* release the last frame */ avctx->release_buffer(avctx, &s->last_frame); av_free(s->buffer1); av_free(s->buffer2); return 0; } AVCodec xan_wc3_decoder = { "xan_wc3", CODEC_TYPE_VIDEO, CODEC_ID_XAN_WC3, sizeof(XanContext), xan_decode_init, NULL, xan_decode_end, xan_decode_frame, CODEC_CAP_DR1, }; /* AVCodec xan_wc4_decoder = { "xan_wc4", CODEC_TYPE_VIDEO, CODEC_ID_XAN_WC4, sizeof(XanContext), xan_decode_init, NULL, xan_decode_end, xan_decode_frame, CODEC_CAP_DR1, }; */