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LZW decoder as separate module plus TIFF LZW support

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Originally committed as revision 6795 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Kostya Shishkov 2006-10-26 04:15:48 +00:00
parent b0c32a70b4
commit ffc5430bc3
6 changed files with 342 additions and 174 deletions
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4
libavcodec/Makefile
View File

@ -81,7 +81,7 @@ OBJS-$(CONFIG_FLASHSV_DECODER) += flashsv.o
OBJS-$(CONFIG_FLIC_DECODER) += flicvideo.o
OBJS-$(CONFIG_FOURXM_DECODER) += 4xm.o
OBJS-$(CONFIG_FRAPS_DECODER) += fraps.o
OBJS-$(CONFIG_GIF_DECODER) += gifdec.o
OBJS-$(CONFIG_GIF_DECODER) += gifdec.o lzw.o
OBJS-$(CONFIG_H261_DECODER) += h261.o
OBJS-$(CONFIG_H261_ENCODER) += h261.o
OBJS-$(CONFIG_H264_DECODER) += h264.o
@ -132,7 +132,7 @@ OBJS-$(CONFIG_SVQ1_ENCODER) += svq1.o
OBJS-$(CONFIG_SVQ3_DECODER) += h264.o
OBJS-$(CONFIG_TARGA_DECODER) += targa.o
OBJS-$(CONFIG_THEORA_DECODER) += vp3.o
OBJS-$(CONFIG_TIFF_DECODER) += tiff.o
OBJS-$(CONFIG_TIFF_DECODER) += tiff.o lzw.o
OBJS-$(CONFIG_TRUEMOTION1_DECODER) += truemotion1.o
OBJS-$(CONFIG_TRUEMOTION2_DECODER) += truemotion2.o
OBJS-$(CONFIG_TRUESPEECH_DECODER) += truespeech.o

4
libavcodec/avcodec.h
View File

@ -37,8 +37,8 @@ extern "C" {
#define AV_STRINGIFY(s) AV_TOSTRING(s)
#define AV_TOSTRING(s) #s
#define LIBAVCODEC_VERSION_INT ((51<<16)+(21<<8)+0)
#define LIBAVCODEC_VERSION 51.21.0
#define LIBAVCODEC_VERSION_INT ((51<<16)+(22<<8)+0)
#define LIBAVCODEC_VERSION 51.22.0
#define LIBAVCODEC_BUILD LIBAVCODEC_VERSION_INT
#define LIBAVCODEC_IDENT "Lavc" AV_STRINGIFY(LIBAVCODEC_VERSION)

176
libavcodec/gifdec.c
View File

@ -24,9 +24,7 @@
#include "avcodec.h"
#include "bytestream.h"
#define MAXBITS 12
#define SIZTABLE (1<<MAXBITS)
#include "lzw.h"
#define GCE_DISPOSAL_NONE 0
#define GCE_DISPOSAL_INPLACE 1
@ -50,175 +48,16 @@ typedef struct GifState {
/* LZW compatible decoder */
uint8_t *bytestream;
int eob_reached;
uint8_t *pbuf, *ebuf;
int bbits;
unsigned int bbuf;
int cursize; /* The current code size */
int curmask;
int codesize;
int clear_code;
int end_code;
int newcodes; /* First available code */
int top_slot; /* Highest code for current size */
int slot; /* Last read code */
int fc, oc;
uint8_t *sp;
uint8_t stack[SIZTABLE];
uint8_t suffix[SIZTABLE];
uint16_t prefix[SIZTABLE];
LZWState *lzw;
/* aux buffers */
uint8_t global_palette[256 * 3];
uint8_t local_palette[256 * 3];
uint8_t buf[256];
} GifState;
static const uint8_t gif87a_sig[6] = "GIF87a";
static const uint8_t gif89a_sig[6] = "GIF89a";
static const uint16_t mask[17] =
{
0x0000, 0x0001, 0x0003, 0x0007,
0x000F, 0x001F, 0x003F, 0x007F,
0x00FF, 0x01FF, 0x03FF, 0x07FF,
0x0FFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF
};
static void GLZWDecodeInit(GifState * s, int csize)
{
/* read buffer */
s->eob_reached = 0;
s->pbuf = s->buf;
s->ebuf = s->buf;
s->bbuf = 0;
s->bbits = 0;
/* decoder */
s->codesize = csize;
s->cursize = s->codesize + 1;
s->curmask = mask[s->cursize];
s->top_slot = 1 << s->cursize;
s->clear_code = 1 << s->codesize;
s->end_code = s->clear_code + 1;
s->slot = s->newcodes = s->clear_code + 2;
s->oc = s->fc = 0;
s->sp = s->stack;
}
/* XXX: optimize */
static inline int GetCode(GifState * s)
{
int c, sizbuf;
uint8_t *ptr;
while (s->bbits < s->cursize) {
ptr = s->pbuf;
if (ptr >= s->ebuf) {
if (!s->eob_reached) {
sizbuf = bytestream_get_byte(&s->bytestream);
s->ebuf = s->buf + sizbuf;
s->pbuf = s->buf;
if (sizbuf > 0) {
bytestream_get_buffer(&s->bytestream, s->buf, sizbuf);
} else {
s->eob_reached = 1;
}
}
ptr = s->pbuf;
}
s->bbuf |= ptr[0] << s->bbits;
ptr++;
s->pbuf = ptr;
s->bbits += 8;
}
c = s->bbuf & s->curmask;
s->bbuf >>= s->cursize;
s->bbits -= s->cursize;
return c;
}
/* NOTE: the algorithm here is inspired from the LZW GIF decoder
written by Steven A. Bennett in 1987. */
/* return the number of byte decoded */
static int GLZWDecode(GifState * s, uint8_t * buf, int len)
{
int l, c, code, oc, fc;
uint8_t *sp;
if (s->end_code < 0)
return 0;
l = len;
sp = s->sp;
oc = s->oc;
fc = s->fc;
while (sp > s->stack) {
*buf++ = *(--sp);
if ((--l) == 0)
goto the_end;
}
for (;;) {
c = GetCode(s);
if (c == s->end_code) {
s->end_code = -1;
break;
} else if (c == s->clear_code) {
s->cursize = s->codesize + 1;
s->curmask = mask[s->cursize];
s->slot = s->newcodes;
s->top_slot = 1 << s->cursize;
while ((c = GetCode(s)) == s->clear_code);
if (c == s->end_code) {
s->end_code = -1;
break;
}
/* test error */
if (c >= s->slot)
c = 0;
fc = oc = c;
*buf++ = c;
if ((--l) == 0)
break;
} else {
code = c;
if (code >= s->slot) {
*sp++ = fc;
code = oc;
}
while (code >= s->newcodes) {
*sp++ = s->suffix[code];
code = s->prefix[code];
}
*sp++ = code;
if (s->slot < s->top_slot) {
s->suffix[s->slot] = fc = code;
s->prefix[s->slot++] = oc;
oc = c;
}
if (s->slot >= s->top_slot) {
if (s->cursize < MAXBITS) {
s->top_slot <<= 1;
s->curmask = mask[++s->cursize];
}
}
while (sp > s->stack) {
*buf++ = *(--sp);
if ((--l) == 0)
goto the_end;
}
}
}
the_end:
s->sp = sp;
s->oc = oc;
s->fc = fc;
return len - l;
}
static int gif_read_image(GifState *s)
{
int left, top, width, height, bits_per_pixel, code_size, flags;
@ -267,7 +106,8 @@ static int gif_read_image(GifState *s)
/* now get the image data */
code_size = bytestream_get_byte(&s->bytestream);
GLZWDecodeInit(s, code_size);
//TODO: add proper data size
ff_lzw_decode_init(s->lzw, code_size, s->bytestream, 0, FF_LZW_GIF);
/* read all the image */
linesize = s->picture.linesize[0];
@ -276,7 +116,7 @@ static int gif_read_image(GifState *s)
pass = 0;
y1 = 0;
for (y = 0; y < height; y++) {
GLZWDecode(s, ptr, width);
ff_lzw_decode(s->lzw, ptr, width);
if (is_interleaved) {
switch(pass) {
default:
@ -314,8 +154,8 @@ static int gif_read_image(GifState *s)
av_free(line);
/* read the garbage data until end marker is found */
while (!s->eob_reached)
GetCode(s);
ff_lzw_decode_tail(s->lzw);
s->bytestream = ff_lzw_cur_ptr(s->lzw);
return 0;
}
@ -445,6 +285,7 @@ static int gif_decode_init(AVCodecContext *avctx)
avcodec_get_frame_defaults(&s->picture);
avctx->coded_frame= &s->picture;
s->picture.data[0] = NULL;
ff_lzw_decode_open(&s->lzw);
return 0;
}
@ -483,6 +324,7 @@ static int gif_decode_close(AVCodecContext *avctx)
{
GifState *s = avctx->priv_data;
ff_lzw_decode_close(&s->lzw);
if(s->picture.data[0])
avctx->release_buffer(avctx, &s->picture);
return 0;

262
libavcodec/lzw.c Normal file
View File

@ -0,0 +1,262 @@
/*
* LZW decoder
* Copyright (c) 2003 Fabrice Bellard.
* Copyright (c) 2006 Konstantin Shishkov.
*
* This file is part of FFmpeg.
*
* FFmpeg 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 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file lzw.c
* @brief LZW decoding routines
* @author Fabrice Bellard
* Modified for use in TIFF by Konstantin Shishkov
*/
#include "avcodec.h"
#include "lzw.h"
#define LZW_MAXBITS 12
#define LZW_SIZTABLE (1<<LZW_MAXBITS)
static const uint16_t mask[17] =
{
0x0000, 0x0001, 0x0003, 0x0007,
0x000F, 0x001F, 0x003F, 0x007F,
0x00FF, 0x01FF, 0x03FF, 0x07FF,
0x0FFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF
};
struct LZWState {
int eob_reached;
uint8_t *pbuf, *ebuf;
int bbits;
unsigned int bbuf;
int mode; ///< Decoder mode
int cursize; ///< The current code size
int curmask;
int codesize;
int clear_code;
int end_code;
int newcodes; ///< First available code
int top_slot; ///< Highest code for current size
int top_slot2; ///< Highest possible code for current size (<=top_slot)
int slot; ///< Last read code
int fc, oc;
uint8_t *sp;
uint8_t stack[LZW_SIZTABLE];
uint8_t suffix[LZW_SIZTABLE];
uint16_t prefix[LZW_SIZTABLE];
int bs; ///< current buffer size for GIF
};
/* get one code from stream */
static int lzw_get_code(struct LZWState * s)
{
int c, sizbuf;
if(s->mode == FF_LZW_GIF) {
while (s->bbits < s->cursize) {
if (!s->bs) {
sizbuf = *s->pbuf++;
s->bs = sizbuf;
if(!sizbuf) {
s->eob_reached = 1;
}
}
s->bbuf |= (*s->pbuf++) << s->bbits;
s->bbits += 8;
s->bs--;
}
c = s->bbuf & s->curmask;
s->bbuf >>= s->cursize;
} else { // TIFF
while (s->bbits < s->cursize) {
if (s->pbuf >= s->ebuf) {
s->eob_reached = 1;
}
s->bbuf = (s->bbuf << 8) | (*s->pbuf++);
s->bbits += 8;
}
c = (s->bbuf >> (s->bbits - s->cursize)) & s->curmask;
}
s->bbits -= s->cursize;
return c;
}
uint8_t* ff_lzw_cur_ptr(LZWState *p)
{
return ((struct LZWState*)p)->pbuf;
}
void ff_lzw_decode_tail(LZWState *p)
{
struct LZWState *s = (struct LZWState *)p;
while(!s->eob_reached)
lzw_get_code(s);
}
void ff_lzw_decode_open(LZWState **p)
{
*p = av_mallocz(sizeof(struct LZWState));
}
void ff_lzw_decode_close(LZWState **p)
{
av_freep(p);
}
/**
* Initialize LZW decoder
* @param s LZW context
* @param csize initial code size in bits
* @param buf input data
* @param buf_size input data size
* @param mode decoder working mode - either GIF or TIFF
*/
int ff_lzw_decode_init(LZWState *p, int csize, uint8_t *buf, int buf_size, int mode)
{
struct LZWState *s = (struct LZWState *)p;
if(csize < 1 || csize > LZW_MAXBITS)
return -1;
/* read buffer */
s->eob_reached = 0;
s->pbuf = buf;
s->ebuf = s->pbuf + buf_size;
s->bbuf = 0;
s->bbits = 0;
s->bs = 0;
/* decoder */
s->codesize = csize;
s->cursize = s->codesize + 1;
s->curmask = mask[s->cursize];
s->top_slot = 1 << s->cursize;
s->clear_code = 1 << s->codesize;
s->end_code = s->clear_code + 1;
s->slot = s->newcodes = s->clear_code + 2;
s->oc = s->fc = 0;
s->sp = s->stack;
s->mode = mode;
switch(s->mode){
case FF_LZW_GIF:
s->top_slot2 = s->top_slot;
break;
case FF_LZW_TIFF:
s->top_slot2 = s->top_slot - 1;
break;
default:
return -1;
}
return 0;
}
/**
* Decode given number of bytes
* NOTE: the algorithm here is inspired from the LZW GIF decoder
* written by Steven A. Bennett in 1987.
*
* @param s LZW context
* @param buf output buffer
* @param len number of bytes to decode
* @return number of bytes decoded
*/
int ff_lzw_decode(LZWState *p, uint8_t *buf, int len){
int l, c, code, oc, fc;
uint8_t *sp;
struct LZWState *s = (struct LZWState *)p;
if (s->end_code < 0)
return 0;
l = len;
sp = s->sp;
oc = s->oc;
fc = s->fc;
while (sp > s->stack) {
*buf++ = *(--sp);
if ((--l) == 0)
goto the_end;
}
for (;;) {
c = lzw_get_code(s);
if (c == s->end_code) {
s->end_code = -1;
break;
} else if (c == s->clear_code) {
s->cursize = s->codesize + 1;
s->curmask = mask[s->cursize];
s->slot = s->newcodes;
s->top_slot = 1 << s->cursize;
s->top_slot2 = s->top_slot;
if(s->mode == FF_LZW_TIFF)
s->top_slot2--;
while ((c = lzw_get_code(s)) == s->clear_code);
if (c == s->end_code) {
s->end_code = -1;
break;
}
/* test error */
if (c >= s->slot)
c = 0;
fc = oc = c;
*buf++ = c;
if ((--l) == 0)
break;
} else {
code = c;
if (code >= s->slot) {
*sp++ = fc;
code = oc;
}
while (code >= s->newcodes) {
*sp++ = s->suffix[code];
code = s->prefix[code];
}
*sp++ = code;
if (s->slot < s->top_slot) {
s->suffix[s->slot] = fc = code;
s->prefix[s->slot++] = oc;
oc = c;
}
if (s->slot >= s->top_slot2) {
if (s->cursize < LZW_MAXBITS) {
s->top_slot <<= 1;
s->top_slot2 = s->top_slot;
if(s->mode == FF_LZW_TIFF)
s->top_slot2--;
s->curmask = mask[++s->cursize];
}
}
while (sp > s->stack) {
*buf++ = *(--sp);
if ((--l) == 0)
goto the_end;
}
}
}
the_end:
s->sp = sp;
s->oc = oc;
s->fc = fc;
return len - l;
}

49
libavcodec/lzw.h Normal file
View File

@ -0,0 +1,49 @@
/*
* LZW decoder
* Copyright (c) 2003 Fabrice Bellard.
* Copyright (c) 2006 Konstantin Shishkov.
*
* This file is part of FFmpeg.
*
* FFmpeg 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 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file lzw.h
* @brief LZW decoding routines
* @author Fabrice Bellard
* Modified for use in TIFF by Konstantin Shishkov
*/
#ifndef LZW_H
#define LZW_H
enum FF_LZW_MODES{
FF_LZW_GIF,
FF_LZW_TIFF
};
/* clients should not know what LZWState is */
typedef void LZWState;
/* first two functions de/allocate memory for LZWState */
void ff_lzw_decode_open(LZWState **p);
void ff_lzw_decode_close(LZWState **p);
int ff_lzw_decode_init(LZWState *s, int csize, uint8_t *buf, int buf_size, int mode);
int ff_lzw_decode(LZWState *s, uint8_t *buf, int len);
uint8_t* ff_lzw_cur_ptr(LZWState *lzw);
void ff_lzw_decode_tail(LZWState *lzw);
#endif

21
libavcodec/tiff.c
View File

@ -23,6 +23,7 @@
#ifdef CONFIG_ZLIB
#include <zlib.h>
#endif
#include "lzw.h"
/* abridged list of TIFF tags */
enum TiffTags{
@ -74,6 +75,7 @@ typedef struct TiffContext {
uint8_t* stripdata;
uint8_t* stripsizes;
int stripsize, stripoff;
LZWState *lzw;
} TiffContext;
static int tget_short(uint8_t **p, int le){
@ -126,6 +128,12 @@ static int tiff_unpack_strip(TiffContext *s, uint8_t* dst, int stride, uint8_t *
return 0;
}
#endif
if(s->compr == TIFF_LZW){
if(ff_lzw_decode_init(s->lzw, 8, src, size, FF_LZW_TIFF) < 0){
av_log(s->avctx, AV_LOG_ERROR, "Error initializing LZW decoder\n");
return -1;
}
}
for(line = 0; line < lines; line++){
if(src - ssrc > size){
av_log(s->avctx, AV_LOG_ERROR, "Source data overread\n");
@ -160,6 +168,13 @@ static int tiff_unpack_strip(TiffContext *s, uint8_t* dst, int stride, uint8_t *
}
}
break;
case TIFF_LZW:
pixels = ff_lzw_decode(s->lzw, dst, width);
if(pixels < width){
av_log(s->avctx, AV_LOG_ERROR, "Decoded only %i bytes of %i\n", pixels, width);
return -1;
}
break;
}
dst += stride;
}
@ -247,6 +262,7 @@ static int tiff_decode_tag(TiffContext *s, uint8_t *start, uint8_t *buf, uint8_t
switch(s->compr){
case TIFF_RAW:
case TIFF_PACKBITS:
case TIFF_LZW:
break;
case TIFF_DEFLATE:
case TIFF_ADOBE_DEFLATE:
@ -256,9 +272,6 @@ static int tiff_decode_tag(TiffContext *s, uint8_t *start, uint8_t *buf, uint8_t
av_log(s->avctx, AV_LOG_ERROR, "Deflate: ZLib not compiled in\n");
return -1;
#endif
case TIFF_LZW:
av_log(s->avctx, AV_LOG_ERROR, "LZW: not implemented yet\n");
return -1;
case TIFF_G3:
av_log(s->avctx, AV_LOG_ERROR, "CCITT G3 compression is not supported\n");
return -1;
@ -405,6 +418,7 @@ static int tiff_init(AVCodecContext *avctx){
avcodec_get_frame_defaults((AVFrame*)&s->picture);
avctx->coded_frame= (AVFrame*)&s->picture;
s->picture.data[0] = NULL;
ff_lzw_decode_open(&s->lzw);
return 0;
}
@ -413,6 +427,7 @@ static int tiff_end(AVCodecContext *avctx)
{
TiffContext * const s = avctx->priv_data;
ff_lzw_decode_close(&s->lzw);
if(s->picture.data[0])
avctx->release_buffer(avctx, &s->picture);
return 0;