mirror of
https://github.com/FFmpeg/FFmpeg.git
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01042d4123
This is required specifically for setting frame->format to -1, otherwise it will be set to 0 = PIX_FMT_YUV420P and code reading the format from the output decoded frame will get misled. In particular fix regressions occurring with the pending vsrc_buffer patch.
568 lines
16 KiB
C
568 lines
16 KiB
C
/*
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* Wing Commander/Xan Video Decoder
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* Copyright (C) 2003 the ffmpeg project
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* Xan video decoder for Wing Commander III computer game
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* by Mario Brito (mbrito@student.dei.uc.pt)
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* and Mike Melanson (melanson@pcisys.net)
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*
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* The xan_wc3 decoder outputs PAL8 data.
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "libavutil/intreadwrite.h"
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#include "avcodec.h"
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#include "bytestream.h"
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#define ALT_BITSTREAM_READER_LE
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#include "get_bits.h"
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// for av_memcpy_backptr
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#include "libavutil/lzo.h"
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#define RUNTIME_GAMMA 0
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#define VGA__TAG MKTAG('V', 'G', 'A', ' ')
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#define PALT_TAG MKTAG('P', 'A', 'L', 'T')
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#define SHOT_TAG MKTAG('S', 'H', 'O', 'T')
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#define PALETTE_COUNT 256
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#define PALETTE_SIZE (PALETTE_COUNT * 3)
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#define PALETTES_MAX 256
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typedef struct XanContext {
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AVCodecContext *avctx;
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AVFrame last_frame;
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AVFrame current_frame;
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const unsigned char *buf;
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int size;
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/* scratch space */
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unsigned char *buffer1;
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int buffer1_size;
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unsigned char *buffer2;
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int buffer2_size;
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unsigned *palettes;
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int palettes_count;
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int cur_palette;
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int frame_size;
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} XanContext;
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static av_cold int xan_decode_init(AVCodecContext *avctx)
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{
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XanContext *s = avctx->priv_data;
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s->avctx = avctx;
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s->frame_size = 0;
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avctx->pix_fmt = PIX_FMT_PAL8;
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s->buffer1_size = avctx->width * avctx->height;
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s->buffer1 = av_malloc(s->buffer1_size);
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if (!s->buffer1)
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return AVERROR(ENOMEM);
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s->buffer2_size = avctx->width * avctx->height;
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s->buffer2 = av_malloc(s->buffer2_size + 130);
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if (!s->buffer2) {
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av_freep(&s->buffer1);
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return AVERROR(ENOMEM);
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}
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avcodec_get_frame_defaults(&s->last_frame);
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avcodec_get_frame_defaults(&s->current_frame);
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return 0;
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}
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static int xan_huffman_decode(unsigned char *dest, const unsigned char *src,
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int dest_len)
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{
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unsigned char byte = *src++;
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unsigned char ival = byte + 0x16;
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const unsigned char * ptr = src + byte*2;
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unsigned char val = ival;
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unsigned char *dest_end = dest + dest_len;
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GetBitContext gb;
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init_get_bits(&gb, ptr, 0); // FIXME: no src size available
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while ( val != 0x16 ) {
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val = src[val - 0x17 + get_bits1(&gb) * byte];
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if ( val < 0x16 ) {
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if (dest >= dest_end)
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return 0;
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*dest++ = val;
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val = ival;
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}
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}
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return 0;
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}
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/**
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* unpack simple compression
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*
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* @param dest destination buffer of dest_len, must be padded with at least 130 bytes
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*/
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static void xan_unpack(unsigned char *dest, const unsigned char *src, int dest_len)
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{
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unsigned char opcode;
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int size;
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unsigned char *dest_end = dest + dest_len;
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while (dest < dest_end) {
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opcode = *src++;
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if (opcode < 0xe0) {
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int size2, back;
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if ( (opcode & 0x80) == 0 ) {
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size = opcode & 3;
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back = ((opcode & 0x60) << 3) + *src++ + 1;
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size2 = ((opcode & 0x1c) >> 2) + 3;
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} else if ( (opcode & 0x40) == 0 ) {
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size = *src >> 6;
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back = (bytestream_get_be16(&src) & 0x3fff) + 1;
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size2 = (opcode & 0x3f) + 4;
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} else {
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size = opcode & 3;
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back = ((opcode & 0x10) << 12) + bytestream_get_be16(&src) + 1;
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size2 = ((opcode & 0x0c) << 6) + *src++ + 5;
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if (size + size2 > dest_end - dest)
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return;
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}
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memcpy(dest, src, size); dest += size; src += size;
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av_memcpy_backptr(dest, back, size2);
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dest += size2;
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} else {
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int finish = opcode >= 0xfc;
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size = finish ? opcode & 3 : ((opcode & 0x1f) << 2) + 4;
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memcpy(dest, src, size); dest += size; src += size;
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if (finish)
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return;
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}
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}
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}
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static inline void xan_wc3_output_pixel_run(XanContext *s,
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const unsigned char *pixel_buffer, int x, int y, int pixel_count)
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{
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int stride;
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int line_inc;
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int index;
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int current_x;
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int width = s->avctx->width;
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unsigned char *palette_plane;
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palette_plane = s->current_frame.data[0];
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stride = s->current_frame.linesize[0];
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line_inc = stride - width;
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index = y * stride + x;
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current_x = x;
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while(pixel_count && (index < s->frame_size)) {
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int count = FFMIN(pixel_count, width - current_x);
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memcpy(palette_plane + index, pixel_buffer, count);
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pixel_count -= count;
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index += count;
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pixel_buffer += count;
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current_x += count;
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if (current_x >= width) {
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index += line_inc;
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current_x = 0;
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}
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}
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}
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static inline void xan_wc3_copy_pixel_run(XanContext *s,
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int x, int y, int pixel_count, int motion_x, int motion_y)
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{
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int stride;
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int line_inc;
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int curframe_index, prevframe_index;
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int curframe_x, prevframe_x;
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int width = s->avctx->width;
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unsigned char *palette_plane, *prev_palette_plane;
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palette_plane = s->current_frame.data[0];
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prev_palette_plane = s->last_frame.data[0];
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stride = s->current_frame.linesize[0];
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line_inc = stride - width;
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curframe_index = y * stride + x;
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curframe_x = x;
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prevframe_index = (y + motion_y) * stride + x + motion_x;
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prevframe_x = x + motion_x;
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while(pixel_count && (curframe_index < s->frame_size)) {
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int count = FFMIN3(pixel_count, width - curframe_x, width - prevframe_x);
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memcpy(palette_plane + curframe_index, prev_palette_plane + prevframe_index, count);
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pixel_count -= count;
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curframe_index += count;
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prevframe_index += count;
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curframe_x += count;
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prevframe_x += count;
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if (curframe_x >= width) {
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curframe_index += line_inc;
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curframe_x = 0;
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}
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if (prevframe_x >= width) {
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prevframe_index += line_inc;
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prevframe_x = 0;
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}
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}
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}
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static void xan_wc3_decode_frame(XanContext *s) {
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int width = s->avctx->width;
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int height = s->avctx->height;
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int total_pixels = width * height;
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unsigned char opcode;
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unsigned char flag = 0;
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int size = 0;
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int motion_x, motion_y;
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int x, y;
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unsigned char *opcode_buffer = s->buffer1;
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int opcode_buffer_size = s->buffer1_size;
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const unsigned char *imagedata_buffer = s->buffer2;
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/* pointers to segments inside the compressed chunk */
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const unsigned char *huffman_segment;
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const unsigned char *size_segment;
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const unsigned char *vector_segment;
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const unsigned char *imagedata_segment;
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huffman_segment = s->buf + AV_RL16(&s->buf[0]);
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size_segment = s->buf + AV_RL16(&s->buf[2]);
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vector_segment = s->buf + AV_RL16(&s->buf[4]);
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imagedata_segment = s->buf + AV_RL16(&s->buf[6]);
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xan_huffman_decode(opcode_buffer, huffman_segment, opcode_buffer_size);
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if (imagedata_segment[0] == 2)
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xan_unpack(s->buffer2, &imagedata_segment[1], s->buffer2_size);
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else
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imagedata_buffer = &imagedata_segment[1];
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/* use the decoded data segments to build the frame */
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x = y = 0;
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while (total_pixels) {
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opcode = *opcode_buffer++;
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size = 0;
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switch (opcode) {
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case 0:
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flag ^= 1;
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continue;
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case 1:
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case 2:
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case 3:
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case 4:
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case 5:
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case 6:
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case 7:
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case 8:
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size = opcode;
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break;
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case 12:
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case 13:
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case 14:
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case 15:
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case 16:
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case 17:
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case 18:
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size += (opcode - 10);
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break;
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case 9:
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case 19:
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size = *size_segment++;
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break;
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case 10:
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case 20:
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size = AV_RB16(&size_segment[0]);
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size_segment += 2;
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break;
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case 11:
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case 21:
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size = AV_RB24(size_segment);
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size_segment += 3;
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break;
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}
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if (opcode < 12) {
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flag ^= 1;
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if (flag) {
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/* run of (size) pixels is unchanged from last frame */
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xan_wc3_copy_pixel_run(s, x, y, size, 0, 0);
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} else {
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/* output a run of pixels from imagedata_buffer */
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xan_wc3_output_pixel_run(s, imagedata_buffer, x, y, size);
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imagedata_buffer += size;
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}
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} else {
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/* run-based motion compensation from last frame */
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motion_x = sign_extend(*vector_segment >> 4, 4);
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motion_y = sign_extend(*vector_segment & 0xF, 4);
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vector_segment++;
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/* copy a run of pixels from the previous frame */
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xan_wc3_copy_pixel_run(s, x, y, size, motion_x, motion_y);
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flag = 0;
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}
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/* coordinate accounting */
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total_pixels -= size;
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y += (x + size) / width;
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x = (x + size) % width;
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}
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}
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#if RUNTIME_GAMMA
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static inline unsigned mul(unsigned a, unsigned b)
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{
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return (a * b) >> 16;
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}
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static inline unsigned pow4(unsigned a)
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{
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unsigned square = mul(a, a);
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return mul(square, square);
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}
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static inline unsigned pow5(unsigned a)
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{
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return mul(pow4(a), a);
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}
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static uint8_t gamma_corr(uint8_t in) {
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unsigned lo, hi = 0xff40, target;
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int i = 15;
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in = (in << 2) | (in >> 6);
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/* equivalent float code:
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if (in >= 252)
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return 253;
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return round(pow(in / 256.0, 0.8) * 256);
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*/
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lo = target = in << 8;
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do {
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unsigned mid = (lo + hi) >> 1;
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unsigned pow = pow5(mid);
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if (pow > target) hi = mid;
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else lo = mid;
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} while (--i);
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return (pow4((lo + hi) >> 1) + 0x80) >> 8;
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}
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#else
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/**
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* This is a gamma correction that xan3 applies to all palette entries.
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*
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* There is a peculiarity, namely that the values are clamped to 253 -
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* it seems likely that this table was calculated by a buggy fixed-point
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* implementation, the one above under RUNTIME_GAMMA behaves like this for
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* example.
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* The exponent value of 0.8 can be explained by this as well, since 0.8 = 4/5
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* and thus pow(x, 0.8) is still easy to calculate.
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* Also, the input values are first rotated to the left by 2.
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*/
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static const uint8_t gamma_lookup[256] = {
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0x00, 0x09, 0x10, 0x16, 0x1C, 0x21, 0x27, 0x2C,
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0x31, 0x35, 0x3A, 0x3F, 0x43, 0x48, 0x4C, 0x50,
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0x54, 0x59, 0x5D, 0x61, 0x65, 0x69, 0x6D, 0x71,
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0x75, 0x79, 0x7D, 0x80, 0x84, 0x88, 0x8C, 0x8F,
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0x93, 0x97, 0x9A, 0x9E, 0xA2, 0xA5, 0xA9, 0xAC,
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0xB0, 0xB3, 0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8,
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0xCB, 0xCF, 0xD2, 0xD5, 0xD9, 0xDC, 0xDF, 0xE3,
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0xE6, 0xE9, 0xED, 0xF0, 0xF3, 0xF6, 0xFA, 0xFD,
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0x03, 0x0B, 0x12, 0x18, 0x1D, 0x23, 0x28, 0x2D,
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0x32, 0x36, 0x3B, 0x40, 0x44, 0x49, 0x4D, 0x51,
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0x56, 0x5A, 0x5E, 0x62, 0x66, 0x6A, 0x6E, 0x72,
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0x76, 0x7A, 0x7D, 0x81, 0x85, 0x89, 0x8D, 0x90,
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0x94, 0x98, 0x9B, 0x9F, 0xA2, 0xA6, 0xAA, 0xAD,
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0xB1, 0xB4, 0xB8, 0xBB, 0xBF, 0xC2, 0xC5, 0xC9,
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0xCC, 0xD0, 0xD3, 0xD6, 0xDA, 0xDD, 0xE0, 0xE4,
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0xE7, 0xEA, 0xED, 0xF1, 0xF4, 0xF7, 0xFA, 0xFD,
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0x05, 0x0D, 0x13, 0x19, 0x1F, 0x24, 0x29, 0x2E,
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0x33, 0x38, 0x3C, 0x41, 0x45, 0x4A, 0x4E, 0x52,
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0x57, 0x5B, 0x5F, 0x63, 0x67, 0x6B, 0x6F, 0x73,
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0x77, 0x7B, 0x7E, 0x82, 0x86, 0x8A, 0x8D, 0x91,
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0x95, 0x99, 0x9C, 0xA0, 0xA3, 0xA7, 0xAA, 0xAE,
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0xB2, 0xB5, 0xB9, 0xBC, 0xBF, 0xC3, 0xC6, 0xCA,
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0xCD, 0xD0, 0xD4, 0xD7, 0xDA, 0xDE, 0xE1, 0xE4,
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0xE8, 0xEB, 0xEE, 0xF1, 0xF5, 0xF8, 0xFB, 0xFD,
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0x07, 0x0E, 0x15, 0x1A, 0x20, 0x25, 0x2A, 0x2F,
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0x34, 0x39, 0x3D, 0x42, 0x46, 0x4B, 0x4F, 0x53,
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0x58, 0x5C, 0x60, 0x64, 0x68, 0x6C, 0x70, 0x74,
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0x78, 0x7C, 0x7F, 0x83, 0x87, 0x8B, 0x8E, 0x92,
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0x96, 0x99, 0x9D, 0xA1, 0xA4, 0xA8, 0xAB, 0xAF,
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0xB2, 0xB6, 0xB9, 0xBD, 0xC0, 0xC4, 0xC7, 0xCB,
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0xCE, 0xD1, 0xD5, 0xD8, 0xDB, 0xDF, 0xE2, 0xE5,
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0xE9, 0xEC, 0xEF, 0xF2, 0xF6, 0xF9, 0xFC, 0xFD
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};
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#endif
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static int xan_decode_frame(AVCodecContext *avctx,
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void *data, int *data_size,
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AVPacket *avpkt)
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{
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const uint8_t *buf = avpkt->data;
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int ret, buf_size = avpkt->size;
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XanContext *s = avctx->priv_data;
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if (avctx->codec->id == CODEC_ID_XAN_WC3) {
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const uint8_t *buf_end = buf + buf_size;
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int tag = 0;
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while (buf_end - buf > 8 && tag != VGA__TAG) {
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unsigned *tmpptr;
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uint32_t new_pal;
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int size;
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int i;
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tag = bytestream_get_le32(&buf);
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size = bytestream_get_be32(&buf);
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size = FFMIN(size, buf_end - buf);
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switch (tag) {
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case PALT_TAG:
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if (size < PALETTE_SIZE)
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return AVERROR_INVALIDDATA;
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if (s->palettes_count >= PALETTES_MAX)
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return AVERROR_INVALIDDATA;
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tmpptr = av_realloc(s->palettes, (s->palettes_count + 1) * AVPALETTE_SIZE);
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if (!tmpptr)
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return AVERROR(ENOMEM);
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s->palettes = tmpptr;
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tmpptr += s->palettes_count * AVPALETTE_COUNT;
|
|
for (i = 0; i < PALETTE_COUNT; i++) {
|
|
#if RUNTIME_GAMMA
|
|
int r = gamma_corr(*buf++);
|
|
int g = gamma_corr(*buf++);
|
|
int b = gamma_corr(*buf++);
|
|
#else
|
|
int r = gamma_lookup[*buf++];
|
|
int g = gamma_lookup[*buf++];
|
|
int b = gamma_lookup[*buf++];
|
|
#endif
|
|
*tmpptr++ = (r << 16) | (g << 8) | b;
|
|
}
|
|
s->palettes_count++;
|
|
break;
|
|
case SHOT_TAG:
|
|
if (size < 4)
|
|
return AVERROR_INVALIDDATA;
|
|
new_pal = bytestream_get_le32(&buf);
|
|
if (new_pal < s->palettes_count) {
|
|
s->cur_palette = new_pal;
|
|
} else
|
|
av_log(avctx, AV_LOG_ERROR, "Invalid palette selected\n");
|
|
break;
|
|
case VGA__TAG:
|
|
break;
|
|
default:
|
|
buf += size;
|
|
break;
|
|
}
|
|
}
|
|
buf_size = buf_end - buf;
|
|
}
|
|
if ((ret = avctx->get_buffer(avctx, &s->current_frame))) {
|
|
av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed\n");
|
|
return ret;
|
|
}
|
|
s->current_frame.reference = 3;
|
|
|
|
if (!s->frame_size)
|
|
s->frame_size = s->current_frame.linesize[0] * s->avctx->height;
|
|
|
|
memcpy(s->current_frame.data[1], s->palettes + s->cur_palette * AVPALETTE_COUNT, AVPALETTE_SIZE);
|
|
|
|
s->buf = buf;
|
|
s->size = buf_size;
|
|
|
|
xan_wc3_decode_frame(s);
|
|
|
|
/* release the last frame if it is allocated */
|
|
if (s->last_frame.data[0])
|
|
avctx->release_buffer(avctx, &s->last_frame);
|
|
|
|
*data_size = sizeof(AVFrame);
|
|
*(AVFrame*)data = s->current_frame;
|
|
|
|
/* shuffle frames */
|
|
FFSWAP(AVFrame, s->current_frame, s->last_frame);
|
|
|
|
/* always report that the buffer was completely consumed */
|
|
return buf_size;
|
|
}
|
|
|
|
static av_cold int xan_decode_end(AVCodecContext *avctx)
|
|
{
|
|
XanContext *s = avctx->priv_data;
|
|
|
|
/* release the frames */
|
|
if (s->last_frame.data[0])
|
|
avctx->release_buffer(avctx, &s->last_frame);
|
|
if (s->current_frame.data[0])
|
|
avctx->release_buffer(avctx, &s->current_frame);
|
|
|
|
av_freep(&s->buffer1);
|
|
av_freep(&s->buffer2);
|
|
av_freep(&s->palettes);
|
|
|
|
return 0;
|
|
}
|
|
|
|
AVCodec ff_xan_wc3_decoder = {
|
|
"xan_wc3",
|
|
AVMEDIA_TYPE_VIDEO,
|
|
CODEC_ID_XAN_WC3,
|
|
sizeof(XanContext),
|
|
xan_decode_init,
|
|
NULL,
|
|
xan_decode_end,
|
|
xan_decode_frame,
|
|
CODEC_CAP_DR1,
|
|
.long_name = NULL_IF_CONFIG_SMALL("Wing Commander III / Xan"),
|
|
};
|
|
|