RepoMirrors
/
ffmpeg
mirror of https://git.ffmpeg.org/ffmpeg.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity
ffmpeg/libavcodec/dv.c

675 lines
20 KiB
C
Raw Blame History

/*
* DV decoder
* Copyright (c) 2002 Fabrice Bellard.
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "avcodec.h"
#include "dsputil.h"
#include "mpegvideo.h"
#include "simple_idct.h"
#define NTSC_FRAME_SIZE 120000
#define PAL_FRAME_SIZE 144000
#define TEX_VLC_BITS 9
typedef struct DVVideoDecodeContext {
AVCodecContext *avctx;
GetBitContext gb;
VLC *vlc;
int sampling_411; /* 0 = 420, 1 = 411 */
int width, height;
UINT8 *current_picture[3]; /* picture structure */
AVVideoFrame picture;
int linesize[3];
DCTELEM block[5*6][64] __align8;
UINT8 dv_zigzag[2][64];
UINT8 idct_permutation[64];
/* XXX: move it to static storage ? */
UINT8 dv_shift[2][22][64];
void (*idct_put[2])(UINT8 *dest, int line_size, DCTELEM *block);
} DVVideoDecodeContext;
#include "dvdata.h"
static VLC dv_vlc;
/* XXX: also include quantization */
static RL_VLC_ELEM *dv_rl_vlc[1];
static void dv_build_unquantize_tables(DVVideoDecodeContext *s)
{
int i, q, j;
/* NOTE: max left shift is 6 */
for(q = 0; q < 22; q++) {
/* 88 unquant */
for(i = 1; i < 64; i++) {
/* 88 table */
j = s->idct_permutation[i];
s->dv_shift[0][q][j] =
dv_quant_shifts[q][dv_88_areas[i]] + 1;
}
/* 248 unquant */
for(i = 1; i < 64; i++) {
/* 248 table */
s->dv_shift[1][q][i] =
dv_quant_shifts[q][dv_248_areas[i]] + 1;
}
}
}
static int dvvideo_decode_init(AVCodecContext *avctx)
{
DVVideoDecodeContext *s = avctx->priv_data;
MpegEncContext s2;
static int done;
if (!done) {
int i;
done = 1;
/* NOTE: as a trick, we use the fact the no codes are unused
to accelerate the parsing of partial codes */
init_vlc(&dv_vlc, TEX_VLC_BITS, NB_DV_VLC,
dv_vlc_len, 1, 1, dv_vlc_bits, 2, 2);
dv_rl_vlc[0] = av_malloc(dv_vlc.table_size * sizeof(RL_VLC_ELEM));
for(i = 0; i < dv_vlc.table_size; i++){
int code= dv_vlc.table[i][0];
int len = dv_vlc.table[i][1];
int level, run;
if(len<0){ //more bits needed
run= 0;
level= code;
} else if (code == (NB_DV_VLC - 1)) {
/* EOB */
run = 0;
level = 256;
} else {
run= dv_vlc_run[code] + 1;
level= dv_vlc_level[code];
}
dv_rl_vlc[0][i].len = len;
dv_rl_vlc[0][i].level = level;
dv_rl_vlc[0][i].run = run;
}
}
/* ugly way to get the idct & scantable */
/* XXX: fix it */
memset(&s2, 0, sizeof(MpegEncContext));
s2.avctx = avctx;
dsputil_init(&s2.dsp, avctx->dsp_mask);
if (DCT_common_init(&s2) < 0)
return -1;
s->idct_put[0] = s2.idct_put;
memcpy(s->idct_permutation, s2.idct_permutation, 64);
memcpy(s->dv_zigzag[0], s2.intra_scantable.permutated, 64);
/* XXX: use MMX also for idct248 */
s->idct_put[1] = simple_idct248_put;
memcpy(s->dv_zigzag[1], dv_248_zigzag, 64);
/* XXX: do it only for constant case */
dv_build_unquantize_tables(s);
return 0;
}
//#define VLC_DEBUG
typedef struct BlockInfo {
const UINT8 *shift_table;
const UINT8 *scan_table;
UINT8 pos; /* position in block */
UINT8 eob_reached; /* true if EOB has been reached */
UINT8 dct_mode;
UINT8 partial_bit_count;
UINT16 partial_bit_buffer;
int shift_offset;
} BlockInfo;
/* block size in bits */
static const UINT16 block_sizes[6] = {
112, 112, 112, 112, 80, 80
};
#ifndef ALT_BITSTREAM_READER
#error only works with ALT_BITSTREAM_READER
#endif
/* decode ac coefs */
static void dv_decode_ac(DVVideoDecodeContext *s,
BlockInfo *mb, INT16 *block, int last_index)
{
int last_re_index;
int shift_offset = mb->shift_offset;
const UINT8 *scan_table = mb->scan_table;
const UINT8 *shift_table = mb->shift_table;
int pos = mb->pos;
int level, pos1, sign, run;
int partial_bit_count;
OPEN_READER(re, &s->gb);
#ifdef VLC_DEBUG
printf("start\n");
#endif
/* if we must parse a partial vlc, we do it here */
partial_bit_count = mb->partial_bit_count;
if (partial_bit_count > 0) {
UINT8 buf[4];
UINT32 v;
int l, l1;
GetBitContext gb1;
/* build the dummy bit buffer */
l = 16 - partial_bit_count;
UPDATE_CACHE(re, &s->gb);
#ifdef VLC_DEBUG
printf("show=%04x\n", SHOW_UBITS(re, &s->gb, 16));
#endif
v = (mb->partial_bit_buffer << l) | SHOW_UBITS(re, &s->gb, l);
buf[0] = v >> 8;
buf[1] = v;
#ifdef VLC_DEBUG
printf("v=%04x cnt=%d %04x\n",
v, partial_bit_count, (mb->partial_bit_buffer << l));
#endif
/* try to read the codeword */
init_get_bits(&gb1, buf, 4);
{
OPEN_READER(re1, &gb1);
UPDATE_CACHE(re1, &gb1);
GET_RL_VLC(level, run, re1, &gb1, dv_rl_vlc[0],
TEX_VLC_BITS, 2);
l = re1_index;
CLOSE_READER(re1, &gb1);
}
#ifdef VLC_DEBUG
printf("****run=%d level=%d size=%d\n", run, level, l);
#endif
/* compute codeword length */
l1 = (level != 256 && level != 0);
/* if too long, we cannot parse */
l -= partial_bit_count;
if ((re_index + l + l1) > last_index)
return;
/* skip read bits */
last_re_index = 0; /* avoid warning */
re_index += l;
/* by definition, if we can read the vlc, all partial bits
will be read (otherwise we could have read the vlc before) */
mb->partial_bit_count = 0;
UPDATE_CACHE(re, &s->gb);
goto handle_vlc;
}
/* get the AC coefficients until last_index is reached */
for(;;) {
UPDATE_CACHE(re, &s->gb);
#ifdef VLC_DEBUG
printf("%2d: bits=%04x index=%d\n",
pos, SHOW_UBITS(re, &s->gb, 16), re_index);
#endif
last_re_index = re_index;
GET_RL_VLC(level, run, re, &s->gb, dv_rl_vlc[0],
TEX_VLC_BITS, 2);
handle_vlc:
#ifdef VLC_DEBUG
printf("run=%d level=%d\n", run, level);
#endif
if (level == 256) {
if (re_index > last_index) {
cannot_read:
/* put position before read code */
re_index = last_re_index;
mb->eob_reached = 0;
break;
}
/* EOB */
mb->eob_reached = 1;
break;
} else if (level != 0) {
if ((re_index + 1) > last_index)
goto cannot_read;
sign = SHOW_SBITS(re, &s->gb, 1);
level = (level ^ sign) - sign;
LAST_SKIP_BITS(re, &s->gb, 1);
pos += run;
/* error */
if (pos >= 64) {
goto read_error;
}
pos1 = scan_table[pos];
level = level << (shift_table[pos1] + shift_offset);
block[pos1] = level;
// printf("run=%d level=%d shift=%d\n", run, level, shift_table[pos1]);
} else {
if (re_index > last_index)
goto cannot_read;
/* level is zero: means run without coding. No
sign is coded */
pos += run;
/* error */
if (pos >= 64) {
read_error:
#if defined(VLC_DEBUG) || 1
printf("error pos=%d\n", pos);
#endif
/* for errors, we consider the eob is reached */
mb->eob_reached = 1;
break;
}
}
}
CLOSE_READER(re, &s->gb);
mb->pos = pos;
}
static inline void bit_copy(PutBitContext *pb, GetBitContext *gb, int bits_left)
{
while (bits_left >= 16) {
put_bits(pb, 16, get_bits(gb, 16));
bits_left -= 16;
}
if (bits_left > 0) {
put_bits(pb, bits_left, get_bits(gb, bits_left));
}
}
/* mb_x and mb_y are in units of 8 pixels */
static inline void dv_decode_video_segment(DVVideoDecodeContext *s,
UINT8 *buf_ptr1,
const UINT16 *mb_pos_ptr)
{
int quant, dc, dct_mode, class1, j;
int mb_index, mb_x, mb_y, v, last_index;
DCTELEM *block, *block1;
int c_offset, bits_left;
UINT8 *y_ptr;
BlockInfo mb_data[5 * 6], *mb, *mb1;
void (*idct_put)(UINT8 *dest, int line_size, DCTELEM *block);
UINT8 *buf_ptr;
PutBitContext pb, vs_pb;
UINT8 mb_bit_buffer[80 + 4]; /* allow some slack */
int mb_bit_count;
UINT8 vs_bit_buffer[5 * 80 + 4]; /* allow some slack */
int vs_bit_count;
memset(s->block, 0, sizeof(s->block));
/* pass 1 : read DC and AC coefficients in blocks */
buf_ptr = buf_ptr1;
block1 = &s->block[0][0];
mb1 = mb_data;
init_put_bits(&vs_pb, vs_bit_buffer, 5 * 80, NULL, NULL);
vs_bit_count = 0;
for(mb_index = 0; mb_index < 5; mb_index++) {
/* skip header */
quant = buf_ptr[3] & 0x0f;
buf_ptr += 4;
init_put_bits(&pb, mb_bit_buffer, 80, NULL, NULL);
mb_bit_count = 0;
mb = mb1;
block = block1;
for(j = 0;j < 6; j++) {
/* NOTE: size is not important here */
init_get_bits(&s->gb, buf_ptr, 14);
/* get the dc */
dc = get_bits(&s->gb, 9);
dc = (dc << (32 - 9)) >> (32 - 9);
dct_mode = get_bits1(&s->gb);
mb->dct_mode = dct_mode;
mb->scan_table = s->dv_zigzag[dct_mode];
class1 = get_bits(&s->gb, 2);
mb->shift_offset = (class1 == 3);
mb->shift_table = s->dv_shift[dct_mode]
[quant + dv_quant_offset[class1]];
dc = dc << 2;
/* convert to unsigned because 128 is not added in the
standard IDCT */
dc += 1024;
block[0] = dc;
last_index = block_sizes[j];
buf_ptr += last_index >> 3;
mb->pos = 0;
mb->partial_bit_count = 0;
dv_decode_ac(s, mb, block, last_index);
/* write the remaining bits in a new buffer only if the
block is finished */
bits_left = last_index - s->gb.index;
if (mb->eob_reached) {
mb->partial_bit_count = 0;
mb_bit_count += bits_left;
bit_copy(&pb, &s->gb, bits_left);
} else {
/* should be < 16 bits otherwise a codeword could have
been parsed */
mb->partial_bit_count = bits_left;
mb->partial_bit_buffer = get_bits(&s->gb, bits_left);
}
block += 64;
mb++;
}
flush_put_bits(&pb);
/* pass 2 : we can do it just after */
#ifdef VLC_DEBUG
printf("***pass 2 size=%d\n", mb_bit_count);
#endif
block = block1;
mb = mb1;
init_get_bits(&s->gb, mb_bit_buffer, 80);
for(j = 0;j < 6; j++) {
if (!mb->eob_reached && s->gb.index < mb_bit_count) {
dv_decode_ac(s, mb, block, mb_bit_count);
/* if still not finished, no need to parse other blocks */
if (!mb->eob_reached) {
/* we could not parse the current AC coefficient,
so we add the remaining bytes */
bits_left = mb_bit_count - s->gb.index;
if (bits_left > 0) {
mb->partial_bit_count += bits_left;
mb->partial_bit_buffer =
(mb->partial_bit_buffer << bits_left) |
get_bits(&s->gb, bits_left);
}
goto next_mb;
}
}
block += 64;
mb++;
}
/* all blocks are finished, so the extra bytes can be used at
the video segment level */
bits_left = mb_bit_count - s->gb.index;
vs_bit_count += bits_left;
bit_copy(&vs_pb, &s->gb, bits_left);
next_mb:
mb1 += 6;
block1 += 6 * 64;
}
/* we need a pass other the whole video segment */
flush_put_bits(&vs_pb);
#ifdef VLC_DEBUG
printf("***pass 3 size=%d\n", vs_bit_count);
#endif
block = &s->block[0][0];
mb = mb_data;
init_get_bits(&s->gb, vs_bit_buffer, 5 * 80);
for(mb_index = 0; mb_index < 5; mb_index++) {
for(j = 0;j < 6; j++) {
if (!mb->eob_reached) {
#ifdef VLC_DEBUG
printf("start %d:%d\n", mb_index, j);
#endif
dv_decode_ac(s, mb, block, vs_bit_count);
}
block += 64;
mb++;
}
}
/* compute idct and place blocks */
block = &s->block[0][0];
mb = mb_data;
for(mb_index = 0; mb_index < 5; mb_index++) {
v = *mb_pos_ptr++;
mb_x = v & 0xff;
mb_y = v >> 8;
y_ptr = s->current_picture[0] + (mb_y * s->linesize[0] * 8) + (mb_x * 8);
if (s->sampling_411)
c_offset = (mb_y * s->linesize[1] * 8) + ((mb_x >> 2) * 8);
else
c_offset = ((mb_y >> 1) * s->linesize[1] * 8) + ((mb_x >> 1) * 8);
for(j = 0;j < 6; j++) {
idct_put = s->idct_put[mb->dct_mode];
if (j < 4) {
if (s->sampling_411 && mb_x < (704 / 8)) {
/* NOTE: at end of line, the macroblock is handled as 420 */
idct_put(y_ptr + (j * 8), s->linesize[0], block);
} else {
idct_put(y_ptr + ((j & 1) * 8) + ((j >> 1) * 8 * s->linesize[0]),
s->linesize[0], block);
}
} else {
if (s->sampling_411 && mb_x >= (704 / 8)) {
uint8_t pixels[64], *c_ptr, *c_ptr1, *ptr;
int y, linesize;
/* NOTE: at end of line, the macroblock is handled as 420 */
idct_put(pixels, 8, block);
linesize = s->linesize[6 - j];
c_ptr = s->current_picture[6 - j] + c_offset;
ptr = pixels;
for(y = 0;y < 8; y++) {
/* convert to 411P */
c_ptr1 = c_ptr + linesize;
c_ptr1[0] = c_ptr[0] = (ptr[0] + ptr[1]) >> 1;
c_ptr1[1] = c_ptr[1] = (ptr[2] + ptr[3]) >> 1;
c_ptr1[2] = c_ptr[2] = (ptr[4] + ptr[5]) >> 1;
c_ptr1[3] = c_ptr[3] = (ptr[6] + ptr[7]) >> 1;
c_ptr += linesize * 2;
ptr += 8;
}
} else {
/* don't ask me why they inverted Cb and Cr ! */
idct_put(s->current_picture[6 - j] + c_offset,
s->linesize[6 - j], block);
}
}
block += 64;
mb++;
}
}
}
/* NOTE: exactly one frame must be given (120000 bytes for NTSC,
144000 bytes for PAL) */
static int dvvideo_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
UINT8 *buf, int buf_size)
{
DVVideoDecodeContext *s = avctx->priv_data;
int sct, dsf, apt, ds, nb_dif_segs, vs, width, height, i, packet_size;
unsigned size;
UINT8 *buf_ptr;
const UINT16 *mb_pos_ptr;
/* parse id */
init_get_bits(&s->gb, buf, buf_size);
sct = get_bits(&s->gb, 3);
if (sct != 0)
return -1;
skip_bits(&s->gb, 5);
get_bits(&s->gb, 4); /* dsn (sequence number */
get_bits(&s->gb, 1); /* fsc (channel number) */
skip_bits(&s->gb, 3);
get_bits(&s->gb, 8); /* dbn (diff block number 0-134) */
dsf = get_bits(&s->gb, 1); /* 0 = NTSC 1 = PAL */
if (get_bits(&s->gb, 1) != 0)
return -1;
skip_bits(&s->gb, 11);
apt = get_bits(&s->gb, 3); /* apt */
get_bits(&s->gb, 1); /* tf1 */
skip_bits(&s->gb, 4);
get_bits(&s->gb, 3); /* ap1 */
get_bits(&s->gb, 1); /* tf2 */
skip_bits(&s->gb, 4);
get_bits(&s->gb, 3); /* ap2 */
get_bits(&s->gb, 1); /* tf3 */
skip_bits(&s->gb, 4);
get_bits(&s->gb, 3); /* ap3 */
/* init size */
width = 720;
if (dsf) {
avctx->frame_rate = 25 * FRAME_RATE_BASE;
packet_size = PAL_FRAME_SIZE;
height = 576;
nb_dif_segs = 12;
} else {
avctx->frame_rate = 30 * FRAME_RATE_BASE;
packet_size = NTSC_FRAME_SIZE;
height = 480;
nb_dif_segs = 10;
}
/* NOTE: we only accept several full frames */
if (buf_size < packet_size)
return -1;
/* XXX: is it correct to assume that 420 is always used in PAL
mode ? */
s->sampling_411 = !dsf;
if (s->sampling_411) {
mb_pos_ptr = dv_place_411;
avctx->pix_fmt = PIX_FMT_YUV411P;
} else {
mb_pos_ptr = dv_place_420;
avctx->pix_fmt = PIX_FMT_YUV420P;
}
avctx->width = width;
avctx->height = height;
s->picture.reference= 0;
if(avctx->get_buffer(avctx, &s->picture) < 0) {
fprintf(stderr, "get_buffer() failed\n");
return -1;
}
for(i=0;i<3;i++) {
s->current_picture[i] = s->picture.data[i];
s->linesize[i] = s->picture.linesize[i];
if (!s->current_picture[i])
return -1;
}
s->width = width;
s->height = height;
/* for each DIF segment */
buf_ptr = buf;
for (ds = 0; ds < nb_dif_segs; ds++) {
buf_ptr += 6 * 80; /* skip DIF segment header */
for(vs = 0; vs < 27; vs++) {
if ((vs % 3) == 0) {
/* skip audio block */
buf_ptr += 80;
}
dv_decode_video_segment(s, buf_ptr, mb_pos_ptr);
buf_ptr += 5 * 80;
mb_pos_ptr += 5;
}
}
emms_c();
/* return image */
*data_size = sizeof(AVVideoFrame);
*(AVVideoFrame*)data= s->picture;
avctx->release_buffer(avctx, &s->picture);
return packet_size;
}
static int dvvideo_decode_end(AVCodecContext *avctx)
{
DVVideoDecodeContext *s = avctx->priv_data;
int i;
if(avctx->get_buffer == avcodec_default_get_buffer){
for(i=0; i<4; i++){
av_freep(&s->picture.base[i]);
s->picture.data[i]= NULL;
}
av_freep(&s->picture.opaque);
}
return 0;
}
AVCodec dvvideo_decoder = {
"dvvideo",
CODEC_TYPE_VIDEO,
CODEC_ID_DVVIDEO,
sizeof(DVVideoDecodeContext),
dvvideo_decode_init,
NULL,
dvvideo_decode_end,
dvvideo_decode_frame,
CODEC_CAP_DR1,
NULL
};
typedef struct DVAudioDecodeContext {
AVCodecContext *avctx;
GetBitContext gb;
} DVAudioDecodeContext;
static int dvaudio_decode_init(AVCodecContext *avctx)
{
// DVAudioDecodeContext *s = avctx->priv_data;
return 0;
}
/* NOTE: exactly one frame must be given (120000 bytes for NTSC,
144000 bytes for PAL) */
static int dvaudio_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
UINT8 *buf, int buf_size)
{
// DVAudioDecodeContext *s = avctx->priv_data;
return buf_size;
}
static int dvaudio_decode_end(AVCodecContext *avctx)
{
// DVAudioDecodeContext *s = avctx->priv_data;
return 0;
}
AVCodec dvaudio_decoder = {
"dvaudio",
CODEC_TYPE_AUDIO,
CODEC_ID_DVAUDIO,
sizeof(DVAudioDecodeContext),
dvaudio_decode_init,
NULL,
dvaudio_decode_end,
dvaudio_decode_frame,
0,
NULL
};
Reference in New Issue View Git Blame Copy Permalink