xenia-project/FFmpeg
1
0
Fork 0
mirror of https://github.com/xenia-project/FFmpeg.git synced 2024-11-24 12:09:55 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity
488fa19a86
FFmpeg/libavcodec/mjpeg.c
Michael Niedermayer 17592475b3 alternative bitstream writer (disabled by default, uncomment #define ALT_BISTREAM_WRITER in common.h if u want to try it) 
Originally committed as revision 295 to svn://svn.ffmpeg.org/ffmpeg/trunk
2002-02-12 15:43:16 +00:00

979 lines
30 KiB
C
Raw Blame History

/*
* MJPEG encoder and decoder
* Copyright (c) 2000, 2001 Gerard Lantau.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
//#define DEBUG
#include "avcodec.h"
#include "dsputil.h"
#include "mpegvideo.h"
typedef struct MJpegContext {
UINT8 huff_size_dc_luminance[12];
UINT16 huff_code_dc_luminance[12];
UINT8 huff_size_dc_chrominance[12];
UINT16 huff_code_dc_chrominance[12];
UINT8 huff_size_ac_luminance[256];
UINT16 huff_code_ac_luminance[256];
UINT8 huff_size_ac_chrominance[256];
UINT16 huff_code_ac_chrominance[256];
} MJpegContext;
#define SOF0 0xc0
#define SOI 0xd8
#define EOI 0xd9
#define DQT 0xdb
#define DHT 0xc4
#define SOS 0xda
#if 0
/* These are the sample quantization tables given in JPEG spec section K.1.
* The spec says that the values given produce "good" quality, and
* when divided by 2, "very good" quality.
*/
static const unsigned char std_luminance_quant_tbl[64] = {
16, 11, 10, 16, 24, 40, 51, 61,
12, 12, 14, 19, 26, 58, 60, 55,
14, 13, 16, 24, 40, 57, 69, 56,
14, 17, 22, 29, 51, 87, 80, 62,
18, 22, 37, 56, 68, 109, 103, 77,
24, 35, 55, 64, 81, 104, 113, 92,
49, 64, 78, 87, 103, 121, 120, 101,
72, 92, 95, 98, 112, 100, 103, 99
};
static const unsigned char std_chrominance_quant_tbl[64] = {
17, 18, 24, 47, 99, 99, 99, 99,
18, 21, 26, 66, 99, 99, 99, 99,
24, 26, 56, 99, 99, 99, 99, 99,
47, 66, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99
};
#endif
/* Set up the standard Huffman tables (cf. JPEG standard section K.3) */
/* IMPORTANT: these are only valid for 8-bit data precision! */
static const UINT8 bits_dc_luminance[17] =
{ /* 0-base */ 0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0 };
static const UINT8 val_dc_luminance[] =
{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 };
static const UINT8 bits_dc_chrominance[17] =
{ /* 0-base */ 0, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 };
static const UINT8 val_dc_chrominance[] =
{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 };
static const UINT8 bits_ac_luminance[17] =
{ /* 0-base */ 0, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d };
static const UINT8 val_ac_luminance[] =
{ 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12,
0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07,
0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08,
0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0,
0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16,
0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28,
0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49,
0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79,
0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,
0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5,
0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4,
0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2,
0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea,
0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
0xf9, 0xfa
};
static const UINT8 bits_ac_chrominance[17] =
{ /* 0-base */ 0, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77 };
static const UINT8 val_ac_chrominance[] =
{ 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21,
0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71,
0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91,
0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0,
0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34,
0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26,
0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38,
0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96,
0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5,
0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4,
0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3,
0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2,
0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda,
0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9,
0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
0xf9, 0xfa
};
/* isn't this function nicer than the one in the libjpeg ? */
static void build_huffman_codes(UINT8 *huff_size, UINT16 *huff_code,
const UINT8 *bits_table, const UINT8 *val_table)
{
int i, j, k,nb, code, sym;
code = 0;
k = 0;
for(i=1;i<=16;i++) {
nb = bits_table[i];
for(j=0;j<nb;j++) {
sym = val_table[k++];
huff_size[sym] = i;
huff_code[sym] = code;
code++;
}
code <<= 1;
}
}
int mjpeg_init(MpegEncContext *s)
{
MJpegContext *m;
m = malloc(sizeof(MJpegContext));
if (!m)
return -1;
/* build all the huffman tables */
build_huffman_codes(m->huff_size_dc_luminance,
m->huff_code_dc_luminance,
bits_dc_luminance,
val_dc_luminance);
build_huffman_codes(m->huff_size_dc_chrominance,
m->huff_code_dc_chrominance,
bits_dc_chrominance,
val_dc_chrominance);
build_huffman_codes(m->huff_size_ac_luminance,
m->huff_code_ac_luminance,
bits_ac_luminance,
val_ac_luminance);
build_huffman_codes(m->huff_size_ac_chrominance,
m->huff_code_ac_chrominance,
bits_ac_chrominance,
val_ac_chrominance);
s->mjpeg_ctx = m;
return 0;
}
void mjpeg_close(MpegEncContext *s)
{
free(s->mjpeg_ctx);
}
static inline void put_marker(PutBitContext *p, int code)
{
put_bits(p, 8, 0xff);
put_bits(p, 8, code);
}
/* table_class: 0 = DC coef, 1 = AC coefs */
static int put_huffman_table(MpegEncContext *s, int table_class, int table_id,
const UINT8 *bits_table, const UINT8 *value_table)
{
PutBitContext *p = &s->pb;
int n, i;
put_bits(p, 4, table_class);
put_bits(p, 4, table_id);
n = 0;
for(i=1;i<=16;i++) {
n += bits_table[i];
put_bits(p, 8, bits_table[i]);
}
for(i=0;i<n;i++)
put_bits(p, 8, value_table[i]);
return n + 17;
}
static void jpeg_table_header(MpegEncContext *s)
{
PutBitContext *p = &s->pb;
int i, j, size;
UINT8 *ptr;
/* quant matrixes */
put_marker(p, DQT);
put_bits(p, 16, 2 + 1 * (1 + 64));
put_bits(p, 4, 0); /* 8 bit precision */
put_bits(p, 4, 0); /* table 0 */
for(i=0;i<64;i++) {
j = zigzag_direct[i];
put_bits(p, 8, s->intra_matrix[j]);
}
#if 0
put_bits(p, 4, 0); /* 8 bit precision */
put_bits(p, 4, 1); /* table 1 */
for(i=0;i<64;i++) {
j = zigzag_direct[i];
put_bits(p, 8, s->chroma_intra_matrix[j]);
}
#endif
/* huffman table */
put_marker(p, DHT);
flush_put_bits(p);
ptr = pbBufPtr(p);
put_bits(p, 16, 0); /* patched later */
size = 2;
size += put_huffman_table(s, 0, 0, bits_dc_luminance, val_dc_luminance);
size += put_huffman_table(s, 0, 1, bits_dc_chrominance, val_dc_chrominance);
size += put_huffman_table(s, 1, 0, bits_ac_luminance, val_ac_luminance);
size += put_huffman_table(s, 1, 1, bits_ac_chrominance, val_ac_chrominance);
ptr[0] = size >> 8;
ptr[1] = size;
}
void mjpeg_picture_header(MpegEncContext *s)
{
put_marker(&s->pb, SOI);
if (s->mjpeg_write_tables) jpeg_table_header(s);
put_marker(&s->pb, SOF0);
put_bits(&s->pb, 16, 17);
put_bits(&s->pb, 8, 8); /* 8 bits/component */
put_bits(&s->pb, 16, s->height);
put_bits(&s->pb, 16, s->width);
put_bits(&s->pb, 8, 3); /* 3 components */
/* Y component */
put_bits(&s->pb, 8, 1); /* component number */
put_bits(&s->pb, 4, s->mjpeg_hsample[0]); /* H factor */
put_bits(&s->pb, 4, s->mjpeg_vsample[0]); /* V factor */
put_bits(&s->pb, 8, 0); /* select matrix */
/* Cb component */
put_bits(&s->pb, 8, 2); /* component number */
put_bits(&s->pb, 4, s->mjpeg_hsample[1]); /* H factor */
put_bits(&s->pb, 4, s->mjpeg_vsample[1]); /* V factor */
put_bits(&s->pb, 8, 0); /* select matrix */
/* Cr component */
put_bits(&s->pb, 8, 3); /* component number */
put_bits(&s->pb, 4, s->mjpeg_hsample[2]); /* H factor */
put_bits(&s->pb, 4, s->mjpeg_vsample[2]); /* V factor */
put_bits(&s->pb, 8, 0); /* select matrix */
/* scan header */
put_marker(&s->pb, SOS);
put_bits(&s->pb, 16, 12); /* length */
put_bits(&s->pb, 8, 3); /* 3 components */
/* Y component */
put_bits(&s->pb, 8, 1); /* index */
put_bits(&s->pb, 4, 0); /* DC huffman table index */
put_bits(&s->pb, 4, 0); /* AC huffman table index */
/* Cb component */
put_bits(&s->pb, 8, 2); /* index */
put_bits(&s->pb, 4, 1); /* DC huffman table index */
put_bits(&s->pb, 4, 1); /* AC huffman table index */
/* Cr component */
put_bits(&s->pb, 8, 3); /* index */
put_bits(&s->pb, 4, 1); /* DC huffman table index */
put_bits(&s->pb, 4, 1); /* AC huffman table index */
put_bits(&s->pb, 8, 0); /* Ss (not used) */
put_bits(&s->pb, 8, 63); /* Se (not used) */
put_bits(&s->pb, 8, 0); /* (not used) */
}
void mjpeg_picture_trailer(MpegEncContext *s)
{
jflush_put_bits(&s->pb);
put_marker(&s->pb, EOI);
}
static inline void encode_dc(MpegEncContext *s, int val,
UINT8 *huff_size, UINT16 *huff_code)
{
int mant, nbits;
if (val == 0) {
jput_bits(&s->pb, huff_size[0], huff_code[0]);
} else {
mant = val;
if (val < 0) {
val = -val;
mant--;
}
/* compute the log (XXX: optimize) */
nbits = 0;
while (val != 0) {
val = val >> 1;
nbits++;
}
jput_bits(&s->pb, huff_size[nbits], huff_code[nbits]);
jput_bits(&s->pb, nbits, mant & ((1 << nbits) - 1));
}
}
static void encode_block(MpegEncContext *s, DCTELEM *block, int n)
{
int mant, nbits, code, i, j;
int component, dc, run, last_index, val;
MJpegContext *m = s->mjpeg_ctx;
UINT8 *huff_size_ac;
UINT16 *huff_code_ac;
/* DC coef */
component = (n <= 3 ? 0 : n - 4 + 1);
dc = block[0]; /* overflow is impossible */
val = dc - s->last_dc[component];
if (n < 4) {
encode_dc(s, val, m->huff_size_dc_luminance, m->huff_code_dc_luminance);
huff_size_ac = m->huff_size_ac_luminance;
huff_code_ac = m->huff_code_ac_luminance;
} else {
encode_dc(s, val, m->huff_size_dc_chrominance, m->huff_code_dc_chrominance);
huff_size_ac = m->huff_size_ac_chrominance;
huff_code_ac = m->huff_code_ac_chrominance;
}
s->last_dc[component] = dc;
/* AC coefs */
run = 0;
last_index = s->block_last_index[n];
for(i=1;i<=last_index;i++) {
j = zigzag_direct[i];
val = block[j];
if (val == 0) {
run++;
} else {
while (run >= 16) {
jput_bits(&s->pb, huff_size_ac[0xf0], huff_code_ac[0xf0]);
run -= 16;
}
mant = val;
if (val < 0) {
val = -val;
mant--;
}
/* compute the log (XXX: optimize) */
nbits = 0;
while (val != 0) {
val = val >> 1;
nbits++;
}
code = (run << 4) | nbits;
jput_bits(&s->pb, huff_size_ac[code], huff_code_ac[code]);
jput_bits(&s->pb, nbits, mant & ((1 << nbits) - 1));
run = 0;
}
}
/* output EOB only if not already 64 values */
if (last_index < 63 || run != 0)
jput_bits(&s->pb, huff_size_ac[0], huff_code_ac[0]);
}
void mjpeg_encode_mb(MpegEncContext *s,
DCTELEM block[6][64])
{
int i;
for(i=0;i<6;i++) {
encode_block(s, block[i], i);
}
}
/******************************************/
/* decoding */
/* compressed picture size */
#define PICTURE_BUFFER_SIZE 100000
#define MAX_COMPONENTS 4
typedef struct MJpegDecodeContext {
GetBitContext gb;
UINT32 header_state;
int start_code; /* current start code */
UINT8 *buf_ptr;
int buffer_size;
int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
INT16 quant_matrixes[4][64];
VLC vlcs[2][4];
int org_width, org_height; /* size given at codec init */
int first_picture; /* true if decoding first picture */
int interlaced; /* true if interlaced */
int bottom_field; /* true if bottom field */
int width, height;
int nb_components;
int component_id[MAX_COMPONENTS];
int h_count[MAX_COMPONENTS]; /* horizontal and vertical count for each component */
int v_count[MAX_COMPONENTS];
int h_max, v_max; /* maximum h and v counts */
int quant_index[4]; /* quant table index for each component */
int last_dc[MAX_COMPONENTS]; /* last DEQUANTIZED dc (XXX: am I right to do that ?) */
UINT8 *current_picture[MAX_COMPONENTS]; /* picture structure */
int linesize[MAX_COMPONENTS];
DCTELEM block[64] __align8;
UINT8 buffer[PICTURE_BUFFER_SIZE];
} MJpegDecodeContext;
static void build_vlc(VLC *vlc, const UINT8 *bits_table, const UINT8 *val_table,
int nb_codes)
{
UINT8 huff_size[256];
UINT16 huff_code[256];
memset(huff_size, 0, sizeof(huff_size));
build_huffman_codes(huff_size, huff_code, bits_table, val_table);
init_vlc(vlc, 9, nb_codes, huff_size, 1, 1, huff_code, 2, 2);
}
static int mjpeg_decode_init(AVCodecContext *avctx)
{
MJpegDecodeContext *s = avctx->priv_data;
s->header_state = 0;
s->mpeg_enc_ctx_allocated = 0;
s->buffer_size = PICTURE_BUFFER_SIZE - 1; /* minus 1 to take into
account FF 00 case */
s->start_code = -1;
s->buf_ptr = s->buffer;
s->first_picture = 1;
s->org_width = avctx->width;
s->org_height = avctx->height;
build_vlc(&s->vlcs[0][0], bits_dc_luminance, val_dc_luminance, 12);
build_vlc(&s->vlcs[0][1], bits_dc_chrominance, val_dc_chrominance, 12);
build_vlc(&s->vlcs[1][0], bits_ac_luminance, val_ac_luminance, 251);
build_vlc(&s->vlcs[1][1], bits_ac_chrominance, val_ac_chrominance, 251);
return 0;
}
/* quantize tables */
static int mjpeg_decode_dqt(MJpegDecodeContext *s,
UINT8 *buf, int buf_size)
{
int len, index, i, j;
init_get_bits(&s->gb, buf, buf_size);
len = get_bits(&s->gb, 16);
len -= 2;
while (len >= 65) {
/* only 8 bit precision handled */
if (get_bits(&s->gb, 4) != 0)
return -1;
index = get_bits(&s->gb, 4);
if (index >= 4)
return -1;
dprintf("index=%d\n", index);
/* read quant table */
for(i=0;i<64;i++) {
j = zigzag_direct[i];
s->quant_matrixes[index][j] = get_bits(&s->gb, 8);
}
len -= 65;
}
return 0;
}
/* decode huffman tables and build VLC decoders */
static int mjpeg_decode_dht(MJpegDecodeContext *s,
UINT8 *buf, int buf_size)
{
int len, index, i, class, n, v, code_max;
UINT8 bits_table[17];
UINT8 val_table[256];
init_get_bits(&s->gb, buf, buf_size);
len = get_bits(&s->gb, 16);
len -= 2;
while (len > 0) {
if (len < 17)
return -1;
class = get_bits(&s->gb, 4);
if (class >= 2)
return -1;
index = get_bits(&s->gb, 4);
if (index >= 4)
return -1;
n = 0;
for(i=1;i<=16;i++) {
bits_table[i] = get_bits(&s->gb, 8);
n += bits_table[i];
}
len -= 17;
if (len < n || n > 256)
return -1;
code_max = 0;
for(i=0;i<n;i++) {
v = get_bits(&s->gb, 8);
if (v > code_max)
code_max = v;
val_table[i] = v;
}
len -= n;
/* build VLC and flush previous vlc if present */
free_vlc(&s->vlcs[class][index]);
dprintf("class=%d index=%d nb_codes=%d\n",
class, index, code_max + 1);
build_vlc(&s->vlcs[class][index], bits_table, val_table, code_max + 1);
}
return 0;
}
static int mjpeg_decode_sof0(MJpegDecodeContext *s,
UINT8 *buf, int buf_size)
{
int len, nb_components, i, width, height;
init_get_bits(&s->gb, buf, buf_size);
/* XXX: verify len field validity */
len = get_bits(&s->gb, 16);
/* only 8 bits/component accepted */
if (get_bits(&s->gb, 8) != 8)
return -1;
height = get_bits(&s->gb, 16);
width = get_bits(&s->gb, 16);
nb_components = get_bits(&s->gb, 8);
if (nb_components <= 0 ||
nb_components > MAX_COMPONENTS)
return -1;
s->nb_components = nb_components;
s->h_max = 1;
s->v_max = 1;
for(i=0;i<nb_components;i++) {
/* component id */
s->component_id[i] = get_bits(&s->gb, 8) - 1;
s->h_count[i] = get_bits(&s->gb, 4);
s->v_count[i] = get_bits(&s->gb, 4);
/* compute hmax and vmax (only used in interleaved case) */
if (s->h_count[i] > s->h_max)
s->h_max = s->h_count[i];
if (s->v_count[i] > s->v_max)
s->v_max = s->v_count[i];
s->quant_index[i] = get_bits(&s->gb, 8);
if (s->quant_index[i] >= 4)
return -1;
dprintf("component %d %d:%d\n", i, s->h_count[i], s->v_count[i]);
}
/* if different size, realloc/alloc picture */
/* XXX: also check h_count and v_count */
if (width != s->width || height != s->height) {
for(i=0;i<MAX_COMPONENTS;i++) {
free(s->current_picture[i]);
s->current_picture[i] = NULL;
}
s->width = width;
s->height = height;
/* test interlaced mode */
if (s->first_picture &&
s->org_height != 0 &&
s->height < ((s->org_height * 3) / 4)) {
s->interlaced = 1;
s->bottom_field = 0;
}
for(i=0;i<nb_components;i++) {
int w, h;
w = (s->width + 8 * s->h_max - 1) / (8 * s->h_max);
h = (s->height + 8 * s->v_max - 1) / (8 * s->v_max);
w = w * 8 * s->h_count[i];
h = h * 8 * s->v_count[i];
if (s->interlaced)
w *= 2;
s->linesize[i] = w;
/* memory test is done in mjpeg_decode_sos() */
s->current_picture[i] = av_mallocz(w * h);
}
s->first_picture = 0;
}
return 0;
}
static inline int decode_dc(MJpegDecodeContext *s, int dc_index)
{
VLC *dc_vlc;
int code, diff;
dc_vlc = &s->vlcs[0][dc_index];
code = get_vlc(&s->gb, dc_vlc);
if (code < 0)
return 0xffff;
if (code == 0) {
diff = 0;
} else {
diff = get_bits(&s->gb, code);
if ((diff & (1 << (code - 1))) == 0)
diff = (-1 << code) | (diff + 1);
}
return diff;
}
/* decode block and dequantize */
static int decode_block(MJpegDecodeContext *s, DCTELEM *block,
int component, int dc_index, int ac_index, int quant_index)
{
int nbits, code, i, j, level;
int run, val;
VLC *ac_vlc;
INT16 *quant_matrix;
quant_matrix = s->quant_matrixes[quant_index];
/* DC coef */
val = decode_dc(s, dc_index);
if (val == 0xffff) {
dprintf("error dc\n");
return -1;
}
val = val * quant_matrix[0] + s->last_dc[component];
s->last_dc[component] = val;
block[0] = val;
/* AC coefs */
ac_vlc = &s->vlcs[1][ac_index];
i = 1;
for(;;) {
code = get_vlc(&s->gb, ac_vlc);
if (code < 0) {
dprintf("error ac\n");
return -1;
}
/* EOB */
if (code == 0)
break;
if (code == 0xf0) {
i += 16;
} else {
run = code >> 4;
nbits = code & 0xf;
level = get_bits(&s->gb, nbits);
if ((level & (1 << (nbits - 1))) == 0)
level = (-1 << nbits) | (level + 1);
i += run;
if (i >= 64) {
dprintf("error count: %d\n", i);
return -1;
}
j = zigzag_direct[i];
block[j] = level * quant_matrix[j];
i++;
if (i >= 64)
break;
}
}
return 0;
}
static int mjpeg_decode_sos(MJpegDecodeContext *s,
UINT8 *buf, int buf_size)
{
int len, nb_components, i, j, n, h, v, ret;
int mb_width, mb_height, mb_x, mb_y, vmax, hmax, index, id;
int comp_index[4];
int dc_index[4];
int ac_index[4];
int nb_blocks[4];
int h_count[4];
int v_count[4];
init_get_bits(&s->gb, buf, buf_size);
/* XXX: verify len field validity */
len = get_bits(&s->gb, 16);
nb_components = get_bits(&s->gb, 8);
/* XXX: only interleaved scan accepted */
if (nb_components != 3)
return -1;
vmax = 0;
hmax = 0;
for(i=0;i<nb_components;i++) {
id = get_bits(&s->gb, 8) - 1;
/* find component index */
for(index=0;index<s->nb_components;index++)
if (id == s->component_id[index])
break;
if (index == s->nb_components)
return -1;
comp_index[i] = index;
nb_blocks[i] = s->h_count[index] * s->v_count[index];
h_count[i] = s->h_count[index];
v_count[i] = s->v_count[index];
dc_index[i] = get_bits(&s->gb, 4);
if (dc_index[i] >= 4)
return -1;
ac_index[i] = get_bits(&s->gb, 4);
if (ac_index[i] >= 4)
return -1;
}
get_bits(&s->gb, 8); /* Ss */
get_bits(&s->gb, 8); /* Se */
get_bits(&s->gb, 8); /* not used */
for(i=0;i<nb_components;i++)
s->last_dc[i] = 1024;
if (nb_components > 1) {
/* interleaved stream */
mb_width = (s->width + s->h_max * 8 - 1) / (s->h_max * 8);
mb_height = (s->height + s->v_max * 8 - 1) / (s->v_max * 8);
} else {
h = s->h_max / s->h_count[comp_index[0]];
v = s->v_max / s->v_count[comp_index[0]];
mb_width = (s->width + h * 8 - 1) / (h * 8);
mb_height = (s->height + v * 8 - 1) / (v * 8);
nb_blocks[0] = 1;
h_count[0] = 1;
v_count[0] = 1;
}
for(mb_y = 0; mb_y < mb_height; mb_y++) {
for(mb_x = 0; mb_x < mb_width; mb_x++) {
for(i=0;i<nb_components;i++) {
UINT8 *ptr;
int x, y, c;
n = nb_blocks[i];
c = comp_index[i];
h = h_count[i];
v = v_count[i];
x = 0;
y = 0;
for(j=0;j<n;j++) {
memset(s->block, 0, sizeof(s->block));
if (decode_block(s, s->block, i,
dc_index[i], ac_index[i],
s->quant_index[c]) < 0) {
dprintf("error %d %d\n", mb_y, mb_x);
ret = -1;
goto the_end;
}
ff_idct (s->block);
ptr = s->current_picture[c] +
(s->linesize[c] * (v * mb_y + y) * 8) +
(h * mb_x + x) * 8;
if (s->interlaced && s->bottom_field)
ptr += s->linesize[c] >> 1;
put_pixels_clamped(s->block, ptr, s->linesize[c]);
if (++x == h) {
x = 0;
y++;
}
}
}
}
}
ret = 0;
the_end:
emms_c();
return ret;
}
/* return the 8 bit start code value and update the search
state. Return -1 if no start code found */
static int find_marker(UINT8 **pbuf_ptr, UINT8 *buf_end,
UINT32 *header_state)
{
UINT8 *buf_ptr;
unsigned int state, v;
int val;
state = *header_state;
buf_ptr = *pbuf_ptr;
if (state) {
/* get marker */
found:
if (buf_ptr < buf_end) {
val = *buf_ptr++;
state = 0;
} else {
val = -1;
}
} else {
while (buf_ptr < buf_end) {
v = *buf_ptr++;
if (v == 0xff) {
state = 1;
goto found;
}
}
val = -1;
}
*pbuf_ptr = buf_ptr;
*header_state = state;
return val;
}
static int mjpeg_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
UINT8 *buf, int buf_size)
{
MJpegDecodeContext *s = avctx->priv_data;
UINT8 *buf_end, *buf_ptr, *buf_start;
int len, code, start_code, input_size, i;
AVPicture *picture = data;
*data_size = 0;
/* no supplementary picture */
if (buf_size == 0)
return 0;
buf_ptr = buf;
buf_end = buf + buf_size;
while (buf_ptr < buf_end) {
buf_start = buf_ptr;
/* find start next marker */
code = find_marker(&buf_ptr, buf_end, &s->header_state);
/* copy to buffer */
len = buf_ptr - buf_start;
if (len + (s->buf_ptr - s->buffer) > s->buffer_size) {
/* data too big : flush */
s->buf_ptr = s->buffer;
if (code > 0)
s->start_code = code;
} else {
memcpy(s->buf_ptr, buf_start, len);
s->buf_ptr += len;
/* if we got FF 00, we copy FF to the stream to unescape FF 00 */
if (code == 0) {
s->buf_ptr--;
} else if (code > 0) {
/* prepare data for next start code */
input_size = s->buf_ptr - s->buffer;
start_code = s->start_code;
s->buf_ptr = s->buffer;
s->start_code = code;
dprintf("marker=%x\n", start_code);
switch(start_code) {
case SOI:
/* nothing to do on SOI */
break;
case DQT:
mjpeg_decode_dqt(s, s->buffer, input_size);
break;
case DHT:
mjpeg_decode_dht(s, s->buffer, input_size);
break;
case SOF0:
mjpeg_decode_sof0(s, s->buffer, input_size);
break;
case SOS:
mjpeg_decode_sos(s, s->buffer, input_size);
if (s->start_code == EOI) {
int l;
if (s->interlaced) {
s->bottom_field ^= 1;
/* if not bottom field, do not output image yet */
if (s->bottom_field)
goto the_end;
}
for(i=0;i<3;i++) {
picture->data[i] = s->current_picture[i];
l = s->linesize[i];
if (s->interlaced)
l >>= 1;
picture->linesize[i] = l;
}
*data_size = sizeof(AVPicture);
avctx->height = s->height;
if (s->interlaced)
avctx->height *= 2;
avctx->width = s->width;
/* XXX: not complete test ! */
switch((s->h_count[0] << 4) | s->v_count[0]) {
case 0x11:
avctx->pix_fmt = PIX_FMT_YUV444P;
break;
case 0x21:
avctx->pix_fmt = PIX_FMT_YUV422P;
break;
default:
case 0x22:
avctx->pix_fmt = PIX_FMT_YUV420P;
break;
}
/* dummy quality */
/* XXX: infer it with matrix */
avctx->quality = 3;
goto the_end;
}
break;
}
}
}
}
the_end:
return buf_ptr - buf;
}
static int mjpeg_decode_end(AVCodecContext *avctx)
{
MJpegDecodeContext *s = avctx->priv_data;
int i, j;
for(i=0;i<MAX_COMPONENTS;i++)
free(s->current_picture[i]);
for(i=0;i<2;i++) {
for(j=0;j<4;j++)
free_vlc(&s->vlcs[i][j]);
}
return 0;
}
AVCodec mjpeg_decoder = {
"mjpeg",
CODEC_TYPE_VIDEO,
CODEC_ID_MJPEG,
sizeof(MJpegDecodeContext),
mjpeg_decode_init,
NULL,
mjpeg_decode_end,
mjpeg_decode_frame,
};
Reference in New Issue View Git Blame Copy Permalink