static void av_noinline qpeg_decode_inter(QpegContext *qctx, uint8_t *dst, int stride, int width, int height, int delta, const uint8_t *ctable, uint8_t *refdata) { int i, j; int code; int filled = 0; int orig_height; if(!refdata) refdata= dst; /* copy prev frame */ for(i = 0; i < height; i++) memcpy(dst + (i * stride), refdata + (i * stride), width); orig_height = height; height--; dst = dst + height * stride; while ((bytestream2_get_bytes_left(&qctx->buffer) > 0) && (height >= 0)) { code = bytestream2_get_byte(&qctx->buffer); if(delta) { /* motion compensation */ while(bytestream2_get_bytes_left(&qctx->buffer) > 0 && (code & 0xF0) == 0xF0) { if(delta == 1) { int me_idx; int me_w, me_h, me_x, me_y; uint8_t *me_plane; int corr, val; /* get block size by index */ me_idx = code & 0xF; me_w = qpeg_table_w[me_idx]; me_h = qpeg_table_h[me_idx]; /* extract motion vector */ corr = bytestream2_get_byte(&qctx->buffer); val = corr >> 4; if(val > 7) val -= 16; me_x = val; val = corr & 0xF; if(val > 7) val -= 16; me_y = val; /* check motion vector */ if ((me_x + filled < 0) || (me_x + me_w + filled > width) || (height - me_y - me_h < 0) || (height - me_y >= orig_height) || (filled + me_w > width) || (height - me_h < 0)) av_log(NULL, AV_LOG_ERROR, "Bogus motion vector (%i,%i), block size %ix%i at %i,%i\n", me_x, me_y, me_w, me_h, filled, height); else { /* do motion compensation */ me_plane = refdata + (filled + me_x) + (height - me_y) * stride; for(j = 0; j < me_h; j++) { for(i = 0; i < me_w; i++) dst[filled + i - (j * stride)] = me_plane[i - (j * stride)]; } } } code = bytestream2_get_byte(&qctx->buffer); } } if(code == 0xE0) /* end-of-picture code */ break; if(code > 0xE0) { /* run code: 0xE1..0xFF */ int p; code &= 0x1F; p = bytestream2_get_byte(&qctx->buffer); for(i = 0; i <= code; i++) { dst[filled++] = p; if(filled >= width) { filled = 0; dst -= stride; height--; if (height < 0) break; } } } else if(code >= 0xC0) { /* copy code: 0xC0..0xDF */ code &= 0x1F; if(code + 1 > bytestream2_get_bytes_left(&qctx->buffer)) break; for(i = 0; i <= code; i++) { dst[filled++] = bytestream2_get_byte(&qctx->buffer); if(filled >= width) { filled = 0; dst -= stride; height--; if (height < 0) break; } } } else if(code >= 0x80) { /* skip code: 0x80..0xBF */ int skip; code &= 0x3F; /* codes 0x80 and 0x81 are actually escape codes, skip value minus constant is in the next byte */ if(!code) skip = bytestream2_get_byte(&qctx->buffer) + 64; else if(code == 1) skip = bytestream2_get_byte(&qctx->buffer) + 320; else skip = code; filled += skip; while( filled >= width) { filled -= width; dst -= stride; height--; if(height < 0) break; } } else { /* zero code treated as one-pixel skip */ if(code) { dst[filled++] = ctable[code & 0x7F]; } else filled++; if(filled >= width) { filled = 0; dst -= stride; height--; } } } }