static int flic_decode_frame_8BPP(AVCodecContext *avctx, void *data, int *data_size, uint8_t *buf, int buf_size) { FlicDecodeContext *s = (FlicDecodeContext *)avctx->priv_data; int stream_ptr = 0; int stream_ptr_after_color_chunk; int pixel_ptr; int palette_ptr; unsigned char palette_idx1; unsigned char palette_idx2; unsigned int frame_size; int num_chunks; unsigned int chunk_size; int chunk_type; int i, j; int color_packets; int color_changes; int color_shift; unsigned char r, g, b; int lines; int compressed_lines; int starting_line; signed short line_packets; int y_ptr; signed char byte_run; int pixel_skip; int pixel_countdown; unsigned char *pixels; int pixel_limit; s->frame.reference = 1; s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE; if (avctx->reget_buffer(avctx, &s->frame) < 0) { av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n"); return -1; } pixels = s->frame.data[0]; pixel_limit = s->avctx->height * s->frame.linesize[0]; frame_size = LE_32(&buf[stream_ptr]); stream_ptr += 6; /* skip the magic number */ num_chunks = LE_16(&buf[stream_ptr]); stream_ptr += 10; /* skip padding */ frame_size -= 16; /* iterate through the chunks */ while ((frame_size > 0) && (num_chunks > 0)) { chunk_size = LE_32(&buf[stream_ptr]); stream_ptr += 4; chunk_type = LE_16(&buf[stream_ptr]); stream_ptr += 2; switch (chunk_type) { case FLI_256_COLOR: case FLI_COLOR: stream_ptr_after_color_chunk = stream_ptr + chunk_size - 6; /* check special case: If this file is from the Magic Carpet * game and uses 6-bit colors even though it reports 256-color * chunks in a 0xAF12-type file (fli_type is set to 0xAF13 during * initialization) */ if ((chunk_type == FLI_256_COLOR) && (s->fli_type != FLC_MAGIC_CARPET_SYNTHETIC_TYPE_CODE)) color_shift = 0; else color_shift = 2; /* set up the palette */ color_packets = LE_16(&buf[stream_ptr]); stream_ptr += 2; palette_ptr = 0; for (i = 0; i < color_packets; i++) { /* first byte is how many colors to skip */ palette_ptr += buf[stream_ptr++]; /* next byte indicates how many entries to change */ color_changes = buf[stream_ptr++]; /* if there are 0 color changes, there are actually 256 */ if (color_changes == 0) color_changes = 256; for (j = 0; j < color_changes; j++) { unsigned int entry; /* wrap around, for good measure */ if ((unsigned)palette_ptr >= 256) palette_ptr = 0; r = buf[stream_ptr++] << color_shift; g = buf[stream_ptr++] << color_shift; b = buf[stream_ptr++] << color_shift; entry = (r << 16) | (g << 8) | b; if (s->palette[palette_ptr] != entry) s->new_palette = 1; s->palette[palette_ptr++] = entry; } } /* color chunks sometimes have weird 16-bit alignment issues; * therefore, take the hardline approach and set the stream_ptr * to the value calculated w.r.t. the size specified by the color * chunk header */ stream_ptr = stream_ptr_after_color_chunk; break; case FLI_DELTA: y_ptr = 0; compressed_lines = LE_16(&buf[stream_ptr]); stream_ptr += 2; while (compressed_lines > 0) { line_packets = LE_16(&buf[stream_ptr]); stream_ptr += 2; if (line_packets < 0) { line_packets = -line_packets; y_ptr += line_packets * s->frame.linesize[0]; } else { compressed_lines--; pixel_ptr = y_ptr; pixel_countdown = s->avctx->width; for (i = 0; i < line_packets; i++) { /* account for the skip bytes */ pixel_skip = buf[stream_ptr++]; pixel_ptr += pixel_skip; pixel_countdown -= pixel_skip; byte_run = buf[stream_ptr++]; if (byte_run < 0) { byte_run = -byte_run; palette_idx1 = buf[stream_ptr++]; palette_idx2 = buf[stream_ptr++]; CHECK_PIXEL_PTR(byte_run); for (j = 0; j < byte_run; j++, pixel_countdown -= 2) { pixels[pixel_ptr++] = palette_idx1; pixels[pixel_ptr++] = palette_idx2; } } else { CHECK_PIXEL_PTR(byte_run * 2); for (j = 0; j < byte_run * 2; j++, pixel_countdown--) { palette_idx1 = buf[stream_ptr++]; pixels[pixel_ptr++] = palette_idx1; } } } y_ptr += s->frame.linesize[0]; } } break; case FLI_LC: /* line compressed */ starting_line = LE_16(&buf[stream_ptr]); stream_ptr += 2; y_ptr = 0; y_ptr += starting_line * s->frame.linesize[0]; compressed_lines = LE_16(&buf[stream_ptr]); stream_ptr += 2; while (compressed_lines > 0) { pixel_ptr = y_ptr; pixel_countdown = s->avctx->width; line_packets = buf[stream_ptr++]; if (line_packets > 0) { for (i = 0; i < line_packets; i++) { /* account for the skip bytes */ pixel_skip = buf[stream_ptr++]; pixel_ptr += pixel_skip; pixel_countdown -= pixel_skip; byte_run = buf[stream_ptr++]; if (byte_run > 0) { CHECK_PIXEL_PTR(byte_run); for (j = 0; j < byte_run; j++, pixel_countdown--) { palette_idx1 = buf[stream_ptr++]; pixels[pixel_ptr++] = palette_idx1; } } else { byte_run = -byte_run; palette_idx1 = buf[stream_ptr++]; CHECK_PIXEL_PTR(byte_run); for (j = 0; j < byte_run; j++, pixel_countdown--) { pixels[pixel_ptr++] = palette_idx1; } } } } y_ptr += s->frame.linesize[0]; compressed_lines--; } break; case FLI_BLACK: /* set the whole frame to color 0 (which is usually black) */ memset(pixels, 0, s->frame.linesize[0] * s->avctx->height); break; case FLI_BRUN: /* Byte run compression: This chunk type only occurs in the first * FLI frame and it will update the entire frame. */ y_ptr = 0; for (lines = 0; lines < s->avctx->height; lines++) { pixel_ptr = y_ptr; /* disregard the line packets; instead, iterate through all * pixels on a row */ stream_ptr++; pixel_countdown = s->avctx->width; while (pixel_countdown > 0) { byte_run = buf[stream_ptr++]; if (byte_run > 0) { palette_idx1 = buf[stream_ptr++]; CHECK_PIXEL_PTR(byte_run); for (j = 0; j < byte_run; j++) { pixels[pixel_ptr++] = palette_idx1; pixel_countdown--; if (pixel_countdown < 0) av_log(avctx, AV_LOG_ERROR, "pixel_countdown < 0 (%d)\n", pixel_countdown); } } else { /* copy bytes if byte_run < 0 */ byte_run = -byte_run; CHECK_PIXEL_PTR(byte_run); for (j = 0; j < byte_run; j++) { palette_idx1 = buf[stream_ptr++]; pixels[pixel_ptr++] = palette_idx1; pixel_countdown--; if (pixel_countdown < 0) av_log(avctx, AV_LOG_ERROR, "pixel_countdown < 0 (%d)\n", pixel_countdown); } } } y_ptr += s->frame.linesize[0]; } break; case FLI_COPY: /* copy the chunk (uncompressed frame) */ if (chunk_size - 6 > s->avctx->width * s->avctx->height) { av_log(avctx, AV_LOG_ERROR, "In chunk FLI_COPY : source data (%d bytes) " \ "bigger than image, skipping chunk\n", chunk_size - 6); stream_ptr += chunk_size - 6; } else { for (y_ptr = 0; y_ptr < s->frame.linesize[0] * s->avctx->height; y_ptr += s->frame.linesize[0]) { memcpy(&pixels[y_ptr], &buf[stream_ptr], s->avctx->width); stream_ptr += s->avctx->width; } } break; case FLI_MINI: /* some sort of a thumbnail? disregard this chunk... */ stream_ptr += chunk_size - 6; break; default: av_log(avctx, AV_LOG_ERROR, "Unrecognized chunk type: %d\n", chunk_type); break; } frame_size -= chunk_size; num_chunks--; } /* by the end of the chunk, the stream ptr should equal the frame * size (minus 1, possibly); if it doesn't, issue a warning */ if ((stream_ptr != buf_size) && (stream_ptr != buf_size - 1)) av_log(avctx, AV_LOG_ERROR, "Processed FLI chunk where chunk size = %d " \ "and final chunk ptr = %d\n", buf_size, stream_ptr); /* make the palette available on the way out */ memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE); if (s->new_palette) { s->frame.palette_has_changed = 1; s->new_palette = 0; } *data_size=sizeof(AVFrame); *(AVFrame*)data = s->frame; return buf_size; }