#include <string.h>
#include "libavutil/intreadwrite.h"
#include "libavutil/mem.h"
#include "avcodec.h"
#include "bytestream.h"
#include "codec_internal.h"
#include "decode.h"
#include "get_bits.h"
Go to the source code of this file.
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static av_cold int | xan_decode_end (AVCodecContext *avctx) |
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static av_cold int | xan_decode_init (AVCodecContext *avctx) |
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static int | xan_huffman_decode (uint8_t *dest, int dest_len, const uint8_t *src, int src_len) |
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static void | xan_unpack (uint8_t *dest, int dest_len, const uint8_t *src, int src_len) |
| unpack simple compression More...
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static void | xan_wc3_output_pixel_run (XanContext *s, AVFrame *frame, const uint8_t *pixel_buffer, int x, int y, int pixel_count) |
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static void | xan_wc3_copy_pixel_run (XanContext *s, AVFrame *frame, int x, int y, int pixel_count, int motion_x, int motion_y) |
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static int | xan_wc3_decode_frame (XanContext *s, AVFrame *frame) |
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static int | xan_decode_frame (AVCodecContext *avctx, AVFrame *frame, int *got_frame, AVPacket *avpkt) |
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Xan video decoder for Wing Commander III computer game by Mario Brito (mbrit.nosp@m.o@st.nosp@m.udent.nosp@m..dei.nosp@m..uc.p.nosp@m.t) and Mike Melanson (melan.nosp@m.son@.nosp@m.pcisy.nosp@m.s.ne.nosp@m.t)
The xan_wc3 decoder outputs PAL8 data.
Definition in file xan.c.
◆ BITSTREAM_READER_LE
#define BITSTREAM_READER_LE |
Definition at line 36 of file xan.c.
◆ RUNTIME_GAMMA
Definition at line 43 of file xan.c.
◆ VGA__TAG
#define VGA__TAG MKTAG('V', 'G', 'A', ' ') |
Definition at line 45 of file xan.c.
◆ PALT_TAG
Definition at line 46 of file xan.c.
◆ SHOT_TAG
#define SHOT_TAG MKTAG('S', 'H', 'O', 'T') |
Definition at line 47 of file xan.c.
◆ PALETTE_COUNT
#define PALETTE_COUNT 256 |
Definition at line 48 of file xan.c.
◆ PALETTE_SIZE
Definition at line 49 of file xan.c.
◆ PALETTES_MAX
Definition at line 50 of file xan.c.
◆ xan_decode_end()
Definition at line 74 of file xan.c.
◆ xan_decode_init()
Definition at line 87 of file xan.c.
◆ xan_huffman_decode()
static int xan_huffman_decode |
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uint8_t * |
dest, |
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int |
dest_len, |
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const uint8_t * |
src, |
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int |
src_len |
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) |
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◆ xan_unpack()
static void xan_unpack |
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uint8_t * |
dest, |
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int |
dest_len, |
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const uint8_t * |
src, |
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int |
src_len |
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unpack simple compression
- Parameters
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dest | destination buffer of dest_len, must be padded with at least 130 bytes |
Definition at line 153 of file xan.c.
Referenced by xan_wc3_decode_frame().
◆ xan_wc3_output_pixel_run()
static void xan_wc3_output_pixel_run |
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XanContext * |
s, |
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AVFrame * |
frame, |
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const uint8_t * |
pixel_buffer, |
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int |
x, |
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int |
y, |
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int |
pixel_count |
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inlinestatic |
◆ xan_wc3_copy_pixel_run()
static void xan_wc3_copy_pixel_run |
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XanContext * |
s, |
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AVFrame * |
frame, |
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int |
x, |
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int |
y, |
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int |
pixel_count, |
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int |
motion_x, |
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int |
motion_y |
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inlinestatic |
◆ xan_wc3_decode_frame()
◆ xan_decode_frame()
◆ gamma_lookup
const uint8_t gamma_lookup[256] |
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This is a gamma correction that xan3 applies to all palette entries.
There is a peculiarity, namely that the values are clamped to 253 - it seems likely that this table was calculated by a buggy fixed-point implementation, the one above under RUNTIME_GAMMA behaves like this for example. The exponent value of 0.8 can be explained by this as well, since 0.8 = 4/5 and thus pow(x, 0.8) is still easy to calculate. Also, the input values are first rotated to the left by 2.
Definition at line 503 of file xan.c.
Referenced by xan_decode_frame().
◆ ff_xan_wc3_decoder
Initial value:= {
.p.name = "xan_wc3",
}
Definition at line 637 of file xan.c.