[FFmpeg-devel] [PATCH] CCITT Group 3 and 4 decompression
Kostya
kostya.shishkov
Tue Dec 23 08:00:57 CET 2008
On Mon, Dec 22, 2008 at 09:06:37PM +0100, Michael Niedermayer wrote:
> On Mon, Dec 22, 2008 at 08:15:06PM +0200, Kostya wrote:
> > On Mon, Dec 22, 2008 at 01:13:53PM +0100, Michael Niedermayer wrote:
> > > On Mon, Dec 22, 2008 at 08:31:55AM +0200, Kostya wrote:
> > > > I need that for resolving issue 750 on roundup.
[...]
> > +{
> > + static VLC_TYPE code_table1[528][2];
> > + static VLC_TYPE code_table2[648][2];
> > + int i;
> > + if(ccitt_group3_2d_vlc.table)
> > + return;
>
> this is not thread safe, this is not the last value written.
>
> and yes these functions can be called from several threads from
> av_find_stream_info() ...
> alternative solutions are welcome as well but as long as av_find_stream_info
> does what it does all init must be thread safe.
now it should be thread safe
[...]
>
> > +static inline int decode_group3_1d_line(AVCodecContext *avctx, GetBitContext *gb,
> > + int pix_left, int *runs)
> > +{
> > + int mode = 0, run = 0, t;
> > + while(pix_left){
> > + t = get_vlc2(gb, ccitt_vlc[mode].table, 9, 2);
> > + run += t;
> > + if(t == -1){
> > + av_log(avctx, AV_LOG_ERROR, "Incorrect code @ %d\n",avctx->width -pix_left);
> > + return -1;
> > + }
> > + if(t >= 64)
> > + continue;
> > + pix_left -= run;
> > + if(pix_left < 0){
> > + av_log(avctx, AV_LOG_ERROR, "Run went out of bounds\n");
> > + return -1;
> > + }
> > + *runs++ = run;
> > + run = 0;
> > + mode = !mode;
> > + }
> > + *runs++ = 0;
> > + return 0;
> > +}
>
> This still has 4 ifs on the most commonly excuted path, the code i provided
> has 2, is there any reason why you do not use something based on just 2?
Your code was wrong since it could not check for incorrect code (t = -1 was
falling into t<64 condition).
> And just the clarify, the "continue" path can only be executed once every
> 64 pixels and thus is of less relevance speedwise.
?
no, it's not a counter. For example, white run of 2000 pixels will be coded
as two values: <1984><16>. See ITU T.4
> also the code can end in a "infinite" and then segfaulting loop through the
> continue
Probably not. When bitreader is out of data it will return zeroes and there's no
all-zero code in the list, so get_vlc2() will return -1 eventually.
> > +
> > +static inline int decode_group3_2d_line(AVCodecContext *avctx, GetBitContext *gb,
> > + int pix_left, int *runs, const int *ref)
> > +{
>
> the function does not look speed critical enough for the inline ...
>
>
> [...]
>
> > +
> > +static void put_line(uint8_t *dst, int size, int width, const int *runs)
> > +{
> > + PutBitContext pb;
> > + int run, t, mode = 0, pix_left = width;
> > +
> > + init_put_bits(&pb, dst, size*8);
> > + while(pix_left > 0){
> > + run = *runs++;
> > + pix_left -= run;
>
> > + while(run){
> > + t = FFMIN(run, 16);
> > + put_sbits(&pb, t, -mode);
> > + run -= t;
> > + }
>
> for(; run>=16; run-=16)
> put_sbits(&pb, 16, -mode);
> put_sbits(&pb, run, -mode);
>
>
> [...]
> > +int ff_ccitt_unpack_group3_1d(AVCodecContext *avctx,
> > + const uint8_t *src, int srcsize,
> > + uint8_t *dst, int height, int stride, int padded)
> > +{
> > + int j;
> > + GetBitContext gb;
> > + int *runs;
> > +
> > + runs = av_malloc(avctx->width * sizeof(runs[0]));
> > + init_get_bits(&gb, src, srcsize*8);
> > + for(j = 0; j < height; j++){
> > + if(padded){
> > + int bits = get_bits_count(&gb) & 7;
> > + if(bits != 4)
> > + skip_bits(&gb, (12 - bits) & 7);
> > + }
> > + if(get_bits(&gb, 12) != 1){
> > + av_log(avctx, AV_LOG_ERROR, "EOL syncmarker not found, resyncing\n");
> > + do{
> > + skip_bits1(&gb);
> > + }while(get_bits_count(&gb) < srcsize*8 && show_bits(&gb, 12) != 1);
> > + if(get_bits_count(&gb) >= srcsize*8)
> > + return -1;
> > + }
>
> how is this supposed to work?
> once a line is damaged and lost there can be 1 line less thus this can
> still run out of data and fail.
it's the question of what to do with damaged data
> [...]
> > +int ff_ccitt_unpack_group3_2d(AVCodecContext *avctx,
> > + const uint8_t *src, int srcsize,
> > + uint8_t *dst, int height, int stride, int padded)
> > +{
> > + int j;
> > + GetBitContext gb;
> > + int *runs, *ref;
> > + int ret;
> > +
> > + runs = av_malloc((avctx->width + 1) * sizeof(runs[0]));
> > + ref = av_malloc((avctx->width + 1) * sizeof(ref[0]));
> > + runs[0] = 0;
> > + ref[0] = 0;
> > + ref[1] = avctx->width;
> > + init_get_bits(&gb, src, srcsize*8);
> > + for(j = 0; j < height; j++){
>
> > + if(padded){
> > + int bits = get_bits_count(&gb) & 7;
> > + if(bits != 4)
> > + skip_bits(&gb, (12 - bits) & 7);
> > + }
> > + if(get_bits(&gb, 12) != 1){
> > + av_log(avctx, AV_LOG_ERROR, "EOL syncmarker not found, resyncing\n");
> > + do{
> > + skip_bits1(&gb);
> > + }while(get_bits_count(&gb) < srcsize*8 && show_bits(&gb, 12) != 1);
> > + if(get_bits_count(&gb) >= srcsize*8)
> > + return -1;
> > + }
>
> duplicate
factorized out
> [...]
> --
> Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
-------------- next part --------------
Index: libavcodec/Makefile
===================================================================
--- libavcodec/Makefile (revision 15993)
+++ libavcodec/Makefile (working copy)
@@ -201,7 +201,7 @@
OBJS-$(CONFIG_THEORA_DECODER) += vp3.o xiph.o vp3dsp.o
OBJS-$(CONFIG_THP_DECODER) += mjpegdec.o mjpeg.o
OBJS-$(CONFIG_TIERTEXSEQVIDEO_DECODER) += tiertexseqv.o
-OBJS-$(CONFIG_TIFF_DECODER) += tiff.o lzw.o
+OBJS-$(CONFIG_TIFF_DECODER) += tiff.o lzw.o faxcompr.o
OBJS-$(CONFIG_TIFF_ENCODER) += tiffenc.o rle.o lzwenc.o
OBJS-$(CONFIG_TRUEMOTION1_DECODER) += truemotion1.o
OBJS-$(CONFIG_TRUEMOTION2_DECODER) += truemotion2.o
Index: libavcodec/tiff.c
===================================================================
--- libavcodec/tiff.c (revision 16268)
+++ libavcodec/tiff.c (working copy)
@@ -30,6 +30,7 @@
#endif
#include "lzw.h"
#include "tiff.h"
+#include "faxcompr.h"
typedef struct TiffContext {
@@ -41,6 +42,7 @@
int le;
int compr;
int invert;
+ int fax_opts;
int predictor;
int strips, rps, sstype;
@@ -103,6 +105,29 @@
return -1;
}
}
+ if(s->compr == TIFF_CCITT_RLE || s->compr == TIFF_G3 || s->compr == TIFF_G4){
+ int i, ret = 0;
+ uint8_t *src2;
+
+ src2 = av_malloc(size);
+ for(i = 0; i < size; i++)
+ src2[i] = ff_reverse[src[i]];
+ if(s->compr == TIFF_G3 && !(s->fax_opts & 1))
+ s->compr = TIFF_CCITT_RLE;
+ switch(s->compr){
+ case TIFF_CCITT_RLE:
+ ret = ff_ccitt_unpack_group3_1d(s->avctx, src2, size, dst, lines, stride);
+ break;
+ case TIFF_G3:
+ ret = ff_ccitt_unpack_group3_2d(s->avctx, src2, size, dst, lines, stride);
+ break;
+ case TIFF_G4:
+ ret = ff_ccitt_unpack_group4 (s->avctx, src2, size, dst, lines, stride);
+ break;
+ }
+ av_free(src2);
+ return ret;
+ }
for(line = 0; line < lines; line++){
if(src - ssrc > size){
av_log(s->avctx, AV_LOG_ERROR, "Source data overread\n");
@@ -265,7 +290,12 @@
case TIFF_RAW:
case TIFF_PACKBITS:
case TIFF_LZW:
+ case TIFF_CCITT_RLE:
break;
+ case TIFF_G3:
+ case TIFF_G4:
+ s->fax_opts = 0;
+ break;
case TIFF_DEFLATE:
case TIFF_ADOBE_DEFLATE:
#ifdef CONFIG_ZLIB
@@ -274,15 +304,6 @@
av_log(s->avctx, AV_LOG_ERROR, "Deflate: ZLib not compiled in\n");
return -1;
#endif
- case TIFF_G3:
- av_log(s->avctx, AV_LOG_ERROR, "CCITT G3 compression is not supported\n");
- return -1;
- case TIFF_G4:
- av_log(s->avctx, AV_LOG_ERROR, "CCITT G4 compression is not supported\n");
- return -1;
- case TIFF_CCITT_RLE:
- av_log(s->avctx, AV_LOG_ERROR, "CCITT RLE compression is not supported\n");
- return -1;
case TIFF_JPEG:
case TIFF_NEWJPEG:
av_log(s->avctx, AV_LOG_ERROR, "JPEG compression is not supported\n");
@@ -373,6 +394,10 @@
return -1;
}
break;
+ case TIFF_T4OPTIONS:
+ case TIFF_T6OPTIONS:
+ s->fax_opts = value;
+ break;
}
return 0;
}
@@ -487,6 +512,7 @@
avctx->coded_frame= (AVFrame*)&s->picture;
s->picture.data[0] = NULL;
ff_lzw_decode_open(&s->lzw);
+ ff_ccitt_unpack_init();
return 0;
}
Index: libavcodec/faxcompr.h
===================================================================
--- libavcodec/faxcompr.h (revision 0)
+++ libavcodec/faxcompr.h (revision 0)
@@ -0,0 +1,58 @@
+/*
+ * CCITT Fax Group 3 and 4 decompression
+ * Copyright (c) 2008 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
+ */
+
+/**
+ * CCITT Fax Group 3 and 4 decompression
+ * @file faxcompr.h
+ * @author Konstantin Shishkov
+ */
+#ifndef AVCODEC_FAXCOMPR_H
+#define AVCODEC_FAXCOMPR_H
+
+#include "avcodec.h"
+
+/**
+ * initialize upacker code
+ */
+void ff_ccitt_unpack_init();
+
+/**
+ * unpack data compressed with CCITT Group 3 1-D method
+ */
+int ff_ccitt_unpack_group3_1d(AVCodecContext *avctx,
+ const uint8_t *src, int srcsize,
+ uint8_t *dst, int height, int stride);
+
+/**
+ * unpack data compressed with CCITT Group 3 2-D method
+ */
+int ff_ccitt_unpack_group3_2d(AVCodecContext *avctx,
+ const uint8_t *src, int srcsize,
+ uint8_t *dst, int height, int stride);
+
+/**
+ * unpack data compressed with CCITT Group 4 1-D method
+ */
+int ff_ccitt_unpack_group4(AVCodecContext *avctx,
+ const uint8_t *src, int srcsize,
+ uint8_t *dst, int height, int stride);
+
+#endif /* AVCODEC_FAXCOMPR_H */
Index: libavcodec/faxcompr.c
===================================================================
--- libavcodec/faxcompr.c (revision 0)
+++ libavcodec/faxcompr.c (revision 0)
@@ -0,0 +1,338 @@
+/*
+ * CCITT Fax Group 3 and 4 decompression
+ * Copyright (c) 2008 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
+ */
+
+/**
+ * CCITT Fax Group 3 and 4 decompression
+ * @file faxcompr.c
+ * @author Konstantin Shishkov
+ */
+#include "avcodec.h"
+#include "bitstream.h"
+#include "faxcompr.h"
+
+#define CCITT_SYMS 104
+
+static const uint16_t ccitt_syms[CCITT_SYMS] = {
+ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
+ 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,
+ 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
+ 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,
+ 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64,
+ 128, 192, 256, 320, 384, 448, 512, 576, 640, 704, 768, 832, 896,
+ 960, 1024, 1088, 1152, 1216, 1280, 1344, 1408, 1472, 1536, 1600, 1664, 1728,
+ 1792, 1856, 1920, 1984, 2048, 2112, 2176, 2240, 2304, 2368, 2432, 2496, 2560
+};
+
+static const uint8_t ccitt_codes_bits[2][CCITT_SYMS] =
+{
+ {
+ 0x35, 0x07, 0x07, 0x08, 0x0B, 0x0C, 0x0E, 0x0F, 0x13, 0x14, 0x07, 0x08, 0x08,
+ 0x03, 0x34, 0x35, 0x2A, 0x2B, 0x27, 0x0C, 0x08, 0x17, 0x03, 0x04, 0x28, 0x2B,
+ 0x13, 0x24, 0x18, 0x02, 0x03, 0x1A, 0x1B, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+ 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x04, 0x05, 0x0A, 0x0B, 0x52, 0x53, 0x54,
+ 0x55, 0x24, 0x25, 0x58, 0x59, 0x5A, 0x5B, 0x4A, 0x4B, 0x32, 0x33, 0x34, 0x1B,
+ 0x12, 0x17, 0x37, 0x36, 0x37, 0x64, 0x65, 0x68, 0x67, 0xCC, 0xCD, 0xD2, 0xD3,
+ 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xDB, 0x98, 0x99, 0x9A, 0x18, 0x9B,
+ 0x08, 0x0C, 0x0D, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x1C, 0x1D, 0x1E, 0x1F
+ },
+ {
+ 0x37, 0x02, 0x03, 0x02, 0x03, 0x03, 0x02, 0x03, 0x05, 0x04, 0x04, 0x05, 0x07,
+ 0x04, 0x07, 0x18, 0x17, 0x18, 0x08, 0x67, 0x68, 0x6C, 0x37, 0x28, 0x17, 0x18,
+ 0xCA, 0xCB, 0xCC, 0xCD, 0x68, 0x69, 0x6A, 0x6B, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6,
+ 0xD7, 0x6C, 0x6D, 0xDA, 0xDB, 0x54, 0x55, 0x56, 0x57, 0x64, 0x65, 0x52, 0x53,
+ 0x24, 0x37, 0x38, 0x27, 0x28, 0x58, 0x59, 0x2B, 0x2C, 0x5A, 0x66, 0x67, 0x0F,
+ 0xC8, 0xC9, 0x5B, 0x33, 0x34, 0x35, 0x6C, 0x6D, 0x4A, 0x4B, 0x4C, 0x4D, 0x72,
+ 0x73, 0x74, 0x75, 0x76, 0x77, 0x52, 0x53, 0x54, 0x55, 0x5A, 0x5B, 0x64, 0x65,
+ 0x08, 0x0C, 0x0D, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x1C, 0x1D, 0x1E, 0x1F
+ }
+};
+
+static const uint8_t ccitt_codes_lens[2][CCITT_SYMS] =
+{
+ {
+ 8, 6, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+ 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+ 8, 8, 8, 8, 5, 5, 6, 7, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9,
+ 9, 9, 9, 9, 9, 9, 9, 9, 9, 6, 9, 11, 11, 11, 12, 12, 12, 12, 12, 12,
+ 12, 12, 12, 12
+ },
+ {
+ 10, 3, 2, 2, 3, 4, 4, 5, 6, 6, 7, 7, 7, 8, 8, 9, 10, 10, 10, 11,
+ 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
+ 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
+ 12, 12, 12, 12, 10, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13, 13,
+ 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 11, 11, 11, 12, 12, 12, 12, 12, 12,
+ 12, 12, 12, 12
+ }
+};
+
+static const uint8_t ccitt_group3_2d_bits[11] = {
+ 1, 1, 2, 2, 2, 1, 3, 3, 3, 1, 1
+};
+
+static const uint8_t ccitt_group3_2d_lens[11] = {
+ 4, 3, 7, 6, 3, 1, 3, 6, 7, 7, 9
+};
+
+static VLC ccitt_vlc[2], ccitt_group3_2d_vlc;
+
+av_cold void ff_ccitt_unpack_init()
+{
+ static VLC_TYPE code_table1[528][2];
+ static VLC_TYPE code_table2[648][2];
+ int i;
+ static int initialized = 0;
+
+ if(initialized)
+ return;
+ ccitt_vlc[0].table = code_table1;
+ ccitt_vlc[0].table_allocated = 528;
+ ccitt_vlc[1].table = code_table2;
+ ccitt_vlc[1].table_allocated = 648;
+ for(i = 0; i < 2; i++){
+ init_vlc_sparse(&ccitt_vlc[i], 9, CCITT_SYMS,
+ ccitt_codes_lens[i], 1, 1,
+ ccitt_codes_bits[i], 1, 1,
+ ccitt_syms, 2, 2,
+ INIT_VLC_USE_NEW_STATIC);
+ }
+ INIT_VLC_STATIC(&ccitt_group3_2d_vlc, 9, 11,
+ ccitt_group3_2d_lens, 1, 1,
+ ccitt_group3_2d_bits, 1, 1, 512);
+ initialized = 1;
+}
+
+
+static int decode_group3_1d_line(AVCodecContext *avctx, GetBitContext *gb,
+ int pix_left, int *runs)
+{
+ int mode = 0, run = 0, t;
+ while(pix_left){
+ t = get_vlc2(gb, ccitt_vlc[mode].table, 9, 2);
+ run += t;
+ if(t == -1){
+ av_log(avctx, AV_LOG_ERROR, "Incorrect code\n");
+ return -1;
+ }
+ if(t >= 64)
+ continue;
+ pix_left -= run;
+ if(pix_left < 0){
+ av_log(avctx, AV_LOG_ERROR, "Run went out of bounds\n");
+ return -1;
+ }
+ *runs++ = run;
+ run = 0;
+ mode = !mode;
+ }
+ *runs++ = 0;
+ return 0;
+}
+
+static int decode_group3_2d_line(AVCodecContext *avctx, GetBitContext *gb,
+ int pix_left, int *runs, const int *ref)
+{
+ int mode = 0, offs = 0, run = 0, saved_run = 0, t;
+ int run_off = 0;
+
+ while(pix_left > 0){
+ int cmode = get_vlc2(gb, ccitt_group3_2d_vlc.table, 9, 1);
+ //sync line pointers
+ while(run_off <= offs && run_off < avctx->width){
+ run_off += *ref++;
+ run_off += *ref++;
+ }
+ if(cmode == -1){
+ av_log(avctx, AV_LOG_ERROR, "Incorrect mode VLC\n");
+ return -1;
+ }
+ if(!cmode){//pass mode
+ run_off += *ref++;
+ run = run_off - offs;
+ run_off += *ref++;
+ pix_left -= run;
+ offs += run;
+ saved_run += run;
+ }else if(cmode == 1){//horizontal mode
+ int k;
+ for(k = 0; k < 2; k++){
+ run = 0;
+ for(;;){
+ t = get_vlc2(gb, ccitt_vlc[mode].table, 9, 2);
+ if(t == -1){
+ av_log(avctx, AV_LOG_ERROR, "Incorrect code\n");
+ return -1;
+ }
+ run += t;
+ if(t < 64)
+ break;
+ }
+ *runs++ = run + saved_run;
+ saved_run = 0;
+ if(pix_left < run){
+ av_log(avctx, AV_LOG_ERROR, "Run went out of bounds\n");
+ return -1;
+ }
+ pix_left -= run;
+ offs += run;
+ mode = !mode;
+ }
+ }else if(cmode == 9 || cmode == 10){
+ av_log(avctx, AV_LOG_ERROR, "Special modes are not supported (yet)\n");
+ return -1;
+ }else{//vertical mode
+ run = run_off - offs + (cmode - 5);
+ if(cmode >= 5)
+ run_off += *ref++;
+ else
+ run_off -= *--ref;
+ pix_left -= run;
+ offs += run;
+ *runs++ = run + saved_run;
+ saved_run = 0;
+ mode = !mode;
+ }
+ }
+ *runs++ = 0;
+ return 0;
+}
+
+static void put_line(uint8_t *dst, int size, int width, const int *runs)
+{
+ PutBitContext pb;
+ int run, mode = 0, pix_left = width;
+
+ init_put_bits(&pb, dst, size*8);
+ while(pix_left > 0){
+ run = *runs++;
+ pix_left -= run;
+ for(; run >= 16; run -= 16)
+ put_sbits(&pb, 16, -mode);
+ if(run)
+ put_sbits(&pb, run, -mode);
+ mode = !mode;
+ }
+}
+
+static int find_group3_syncmarker(GetBitContext *gb, int srcsize)
+{
+ int ret = 0;
+ while(show_bits(gb, 12) != 1){
+ skip_bits1(gb);
+ ret = 1;
+ if(get_bits_count(gb) >= srcsize)
+ return -1;
+ }
+ skip_bits(gb, 12);
+ return ret;
+}
+
+int ff_ccitt_unpack_group3_1d(AVCodecContext *avctx,
+ const uint8_t *src, int srcsize,
+ uint8_t *dst, int height, int stride)
+{
+ int j;
+ GetBitContext gb;
+ int *runs;
+
+ runs = av_malloc(avctx->width * sizeof(runs[0]));
+ init_get_bits(&gb, src, srcsize*8);
+ for(j = 0; j < height; j++){
+ if(find_group3_syncmarker(&gb, srcsize*8) < 0)
+ break;
+ if(decode_group3_1d_line(avctx, &gb, avctx->width, runs) < 0){
+ av_log(avctx, AV_LOG_ERROR, "Error decoding line\n");
+ continue;
+ }
+ put_line(dst, stride, avctx->width, runs);
+ dst += stride;
+ }
+ av_free(runs);
+ return 0;
+}
+
+int ff_ccitt_unpack_group3_2d(AVCodecContext *avctx,
+ const uint8_t *src, int srcsize,
+ uint8_t *dst, int height, int stride)
+{
+ int j;
+ GetBitContext gb;
+ int *runs, *ref;
+ int ret;
+
+ runs = av_malloc((avctx->width + 1) * sizeof(runs[0]));
+ ref = av_malloc((avctx->width + 1) * sizeof(ref[0]));
+ runs[0] = 0;
+ ref[0] = 0;
+ ref[1] = avctx->width;
+ init_get_bits(&gb, src, srcsize*8);
+ for(j = 0; j < height; j++){
+ if(find_group3_syncmarker(&gb, srcsize*8) < 0)
+ break;
+ if(get_bits1(&gb))
+ ret = decode_group3_1d_line(avctx, &gb, avctx->width, runs + 1);
+ else
+ ret = decode_group3_2d_line(avctx, &gb, avctx->width, runs + 1, ref);
+ if(ret < 0){
+ av_free(runs);
+ av_free(ref);
+ return -1;
+ }
+ put_line(dst, stride, avctx->width, runs + 1);
+ FFSWAP(int*, runs, ref);
+ dst += stride;
+ }
+ av_free(runs);
+ av_free(ref);
+ return 0;
+}
+
+int ff_ccitt_unpack_group4(AVCodecContext *avctx,
+ const uint8_t *src, int srcsize,
+ uint8_t *dst, int height, int stride)
+{
+ int j;
+ GetBitContext gb;
+ int *runs, *ref;
+ int ret;
+
+ runs = av_malloc((avctx->width + 1) * sizeof(runs[0]));
+ ref = av_malloc((avctx->width + 1) * sizeof(ref[0]));
+ runs[0] = 0;
+ ref[0] = 0;
+ ref[1] = avctx->width;
+ init_get_bits(&gb, src, srcsize*8);
+ for(j = 0; j < height; j++){
+ ret = decode_group3_2d_line(avctx, &gb, avctx->width, runs + 1, ref);
+ if(ret < 0){
+ av_free(runs);
+ av_free(ref);
+ return -1;
+ }
+ put_line(dst, stride, avctx->width, runs + 1);
+ FFSWAP(int*, runs, ref);
+ dst += stride;
+ }
+ av_free(runs);
+ av_free(ref);
+ return 0;
+}
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