0,0 → 1,870 |
/* |
* Microsoft Screen 3 (aka Microsoft ATC Screen) decoder |
* Copyright (c) 2012 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 |
* Microsoft Screen 3 (aka Microsoft ATC Screen) decoder |
*/ |
|
#include "avcodec.h" |
#include "bytestream.h" |
#include "dsputil.h" |
#include "internal.h" |
#include "mss34dsp.h" |
|
#define HEADER_SIZE 27 |
|
#define MODEL2_SCALE 13 |
#define MODEL_SCALE 15 |
#define MODEL256_SEC_SCALE 9 |
|
typedef struct Model2 { |
int upd_val, till_rescale; |
unsigned zero_freq, zero_weight; |
unsigned total_freq, total_weight; |
} Model2; |
|
typedef struct Model { |
int weights[16], freqs[16]; |
int num_syms; |
int tot_weight; |
int upd_val, max_upd_val, till_rescale; |
} Model; |
|
typedef struct Model256 { |
int weights[256], freqs[256]; |
int tot_weight; |
int secondary[68]; |
int sec_size; |
int upd_val, max_upd_val, till_rescale; |
} Model256; |
|
#define RAC_BOTTOM 0x01000000 |
typedef struct RangeCoder { |
const uint8_t *src, *src_end; |
|
uint32_t range, low; |
int got_error; |
} RangeCoder; |
|
enum BlockType { |
FILL_BLOCK = 0, |
IMAGE_BLOCK, |
DCT_BLOCK, |
HAAR_BLOCK, |
SKIP_BLOCK |
}; |
|
typedef struct BlockTypeContext { |
int last_type; |
Model bt_model[5]; |
} BlockTypeContext; |
|
typedef struct FillBlockCoder { |
int fill_val; |
Model coef_model; |
} FillBlockCoder; |
|
typedef struct ImageBlockCoder { |
Model256 esc_model, vec_entry_model; |
Model vec_size_model; |
Model vq_model[125]; |
} ImageBlockCoder; |
|
typedef struct DCTBlockCoder { |
int *prev_dc; |
int prev_dc_stride; |
int prev_dc_height; |
int quality; |
uint16_t qmat[64]; |
Model dc_model; |
Model2 sign_model; |
Model256 ac_model; |
} DCTBlockCoder; |
|
typedef struct HaarBlockCoder { |
int quality, scale; |
Model256 coef_model; |
Model coef_hi_model; |
} HaarBlockCoder; |
|
typedef struct MSS3Context { |
AVCodecContext *avctx; |
AVFrame *pic; |
|
int got_error; |
RangeCoder coder; |
BlockTypeContext btype[3]; |
FillBlockCoder fill_coder[3]; |
ImageBlockCoder image_coder[3]; |
DCTBlockCoder dct_coder[3]; |
HaarBlockCoder haar_coder[3]; |
|
int dctblock[64]; |
int hblock[16 * 16]; |
} MSS3Context; |
|
|
static void model2_reset(Model2 *m) |
{ |
m->zero_weight = 1; |
m->total_weight = 2; |
m->zero_freq = 0x1000; |
m->total_freq = 0x2000; |
m->upd_val = 4; |
m->till_rescale = 4; |
} |
|
static void model2_update(Model2 *m, int bit) |
{ |
unsigned scale; |
|
if (!bit) |
m->zero_weight++; |
m->till_rescale--; |
if (m->till_rescale) |
return; |
|
m->total_weight += m->upd_val; |
if (m->total_weight > 0x2000) { |
m->total_weight = (m->total_weight + 1) >> 1; |
m->zero_weight = (m->zero_weight + 1) >> 1; |
if (m->total_weight == m->zero_weight) |
m->total_weight = m->zero_weight + 1; |
} |
m->upd_val = m->upd_val * 5 >> 2; |
if (m->upd_val > 64) |
m->upd_val = 64; |
scale = 0x80000000u / m->total_weight; |
m->zero_freq = m->zero_weight * scale >> 18; |
m->total_freq = m->total_weight * scale >> 18; |
m->till_rescale = m->upd_val; |
} |
|
static void model_update(Model *m, int val) |
{ |
int i, sum = 0; |
unsigned scale; |
|
m->weights[val]++; |
m->till_rescale--; |
if (m->till_rescale) |
return; |
m->tot_weight += m->upd_val; |
|
if (m->tot_weight > 0x8000) { |
m->tot_weight = 0; |
for (i = 0; i < m->num_syms; i++) { |
m->weights[i] = (m->weights[i] + 1) >> 1; |
m->tot_weight += m->weights[i]; |
} |
} |
scale = 0x80000000u / m->tot_weight; |
for (i = 0; i < m->num_syms; i++) { |
m->freqs[i] = sum * scale >> 16; |
sum += m->weights[i]; |
} |
|
m->upd_val = m->upd_val * 5 >> 2; |
if (m->upd_val > m->max_upd_val) |
m->upd_val = m->max_upd_val; |
m->till_rescale = m->upd_val; |
} |
|
static void model_reset(Model *m) |
{ |
int i; |
|
m->tot_weight = 0; |
for (i = 0; i < m->num_syms - 1; i++) |
m->weights[i] = 1; |
m->weights[m->num_syms - 1] = 0; |
|
m->upd_val = m->num_syms; |
m->till_rescale = 1; |
model_update(m, m->num_syms - 1); |
m->till_rescale = |
m->upd_val = (m->num_syms + 6) >> 1; |
} |
|
static av_cold void model_init(Model *m, int num_syms) |
{ |
m->num_syms = num_syms; |
m->max_upd_val = 8 * num_syms + 48; |
|
model_reset(m); |
} |
|
static void model256_update(Model256 *m, int val) |
{ |
int i, sum = 0; |
unsigned scale; |
int send, sidx = 1; |
|
m->weights[val]++; |
m->till_rescale--; |
if (m->till_rescale) |
return; |
m->tot_weight += m->upd_val; |
|
if (m->tot_weight > 0x8000) { |
m->tot_weight = 0; |
for (i = 0; i < 256; i++) { |
m->weights[i] = (m->weights[i] + 1) >> 1; |
m->tot_weight += m->weights[i]; |
} |
} |
scale = 0x80000000u / m->tot_weight; |
m->secondary[0] = 0; |
for (i = 0; i < 256; i++) { |
m->freqs[i] = sum * scale >> 16; |
sum += m->weights[i]; |
send = m->freqs[i] >> MODEL256_SEC_SCALE; |
while (sidx <= send) |
m->secondary[sidx++] = i - 1; |
} |
while (sidx < m->sec_size) |
m->secondary[sidx++] = 255; |
|
m->upd_val = m->upd_val * 5 >> 2; |
if (m->upd_val > m->max_upd_val) |
m->upd_val = m->max_upd_val; |
m->till_rescale = m->upd_val; |
} |
|
static void model256_reset(Model256 *m) |
{ |
int i; |
|
for (i = 0; i < 255; i++) |
m->weights[i] = 1; |
m->weights[255] = 0; |
|
m->tot_weight = 0; |
m->upd_val = 256; |
m->till_rescale = 1; |
model256_update(m, 255); |
m->till_rescale = |
m->upd_val = (256 + 6) >> 1; |
} |
|
static av_cold void model256_init(Model256 *m) |
{ |
m->max_upd_val = 8 * 256 + 48; |
m->sec_size = (1 << 6) + 2; |
|
model256_reset(m); |
} |
|
static void rac_init(RangeCoder *c, const uint8_t *src, int size) |
{ |
int i; |
|
c->src = src; |
c->src_end = src + size; |
c->low = 0; |
for (i = 0; i < FFMIN(size, 4); i++) |
c->low = (c->low << 8) | *c->src++; |
c->range = 0xFFFFFFFF; |
c->got_error = 0; |
} |
|
static void rac_normalise(RangeCoder *c) |
{ |
for (;;) { |
c->range <<= 8; |
c->low <<= 8; |
if (c->src < c->src_end) { |
c->low |= *c->src++; |
} else if (!c->low) { |
c->got_error = 1; |
c->low = 1; |
} |
if (c->range >= RAC_BOTTOM) |
return; |
} |
} |
|
static int rac_get_bit(RangeCoder *c) |
{ |
int bit; |
|
c->range >>= 1; |
|
bit = (c->range <= c->low); |
if (bit) |
c->low -= c->range; |
|
if (c->range < RAC_BOTTOM) |
rac_normalise(c); |
|
return bit; |
} |
|
static int rac_get_bits(RangeCoder *c, int nbits) |
{ |
int val; |
|
c->range >>= nbits; |
val = c->low / c->range; |
c->low -= c->range * val; |
|
if (c->range < RAC_BOTTOM) |
rac_normalise(c); |
|
return val; |
} |
|
static int rac_get_model2_sym(RangeCoder *c, Model2 *m) |
{ |
int bit, helper; |
|
helper = m->zero_freq * (c->range >> MODEL2_SCALE); |
bit = (c->low >= helper); |
if (bit) { |
c->low -= helper; |
c->range -= helper; |
} else { |
c->range = helper; |
} |
|
if (c->range < RAC_BOTTOM) |
rac_normalise(c); |
|
model2_update(m, bit); |
|
return bit; |
} |
|
static int rac_get_model_sym(RangeCoder *c, Model *m) |
{ |
int prob, prob2, helper, val; |
int end, end2; |
|
prob = 0; |
prob2 = c->range; |
c->range >>= MODEL_SCALE; |
val = 0; |
end = m->num_syms >> 1; |
end2 = m->num_syms; |
do { |
helper = m->freqs[end] * c->range; |
if (helper <= c->low) { |
val = end; |
prob = helper; |
} else { |
end2 = end; |
prob2 = helper; |
} |
end = (end2 + val) >> 1; |
} while (end != val); |
c->low -= prob; |
c->range = prob2 - prob; |
if (c->range < RAC_BOTTOM) |
rac_normalise(c); |
|
model_update(m, val); |
|
return val; |
} |
|
static int rac_get_model256_sym(RangeCoder *c, Model256 *m) |
{ |
int prob, prob2, helper, val; |
int start, end; |
int ssym; |
|
prob2 = c->range; |
c->range >>= MODEL_SCALE; |
|
helper = c->low / c->range; |
ssym = helper >> MODEL256_SEC_SCALE; |
val = m->secondary[ssym]; |
|
end = start = m->secondary[ssym + 1] + 1; |
while (end > val + 1) { |
ssym = (end + val) >> 1; |
if (m->freqs[ssym] <= helper) { |
end = start; |
val = ssym; |
} else { |
end = (end + val) >> 1; |
start = ssym; |
} |
} |
prob = m->freqs[val] * c->range; |
if (val != 255) |
prob2 = m->freqs[val + 1] * c->range; |
|
c->low -= prob; |
c->range = prob2 - prob; |
if (c->range < RAC_BOTTOM) |
rac_normalise(c); |
|
model256_update(m, val); |
|
return val; |
} |
|
static int decode_block_type(RangeCoder *c, BlockTypeContext *bt) |
{ |
bt->last_type = rac_get_model_sym(c, &bt->bt_model[bt->last_type]); |
|
return bt->last_type; |
} |
|
static int decode_coeff(RangeCoder *c, Model *m) |
{ |
int val, sign; |
|
val = rac_get_model_sym(c, m); |
if (val) { |
sign = rac_get_bit(c); |
if (val > 1) { |
val--; |
val = (1 << val) + rac_get_bits(c, val); |
} |
if (!sign) |
val = -val; |
} |
|
return val; |
} |
|
static void decode_fill_block(RangeCoder *c, FillBlockCoder *fc, |
uint8_t *dst, int stride, int block_size) |
{ |
int i; |
|
fc->fill_val += decode_coeff(c, &fc->coef_model); |
|
for (i = 0; i < block_size; i++, dst += stride) |
memset(dst, fc->fill_val, block_size); |
} |
|
static void decode_image_block(RangeCoder *c, ImageBlockCoder *ic, |
uint8_t *dst, int stride, int block_size) |
{ |
int i, j; |
int vec_size; |
int vec[4]; |
int prev_line[16]; |
int A, B, C; |
|
vec_size = rac_get_model_sym(c, &ic->vec_size_model) + 2; |
for (i = 0; i < vec_size; i++) |
vec[i] = rac_get_model256_sym(c, &ic->vec_entry_model); |
for (; i < 4; i++) |
vec[i] = 0; |
memset(prev_line, 0, sizeof(prev_line)); |
|
for (j = 0; j < block_size; j++) { |
A = 0; |
B = 0; |
for (i = 0; i < block_size; i++) { |
C = B; |
B = prev_line[i]; |
A = rac_get_model_sym(c, &ic->vq_model[A + B * 5 + C * 25]); |
|
prev_line[i] = A; |
if (A < 4) |
dst[i] = vec[A]; |
else |
dst[i] = rac_get_model256_sym(c, &ic->esc_model); |
} |
dst += stride; |
} |
} |
|
static int decode_dct(RangeCoder *c, DCTBlockCoder *bc, int *block, |
int bx, int by) |
{ |
int skip, val, sign, pos = 1, zz_pos, dc; |
int blk_pos = bx + by * bc->prev_dc_stride; |
|
memset(block, 0, sizeof(*block) * 64); |
|
dc = decode_coeff(c, &bc->dc_model); |
if (by) { |
if (bx) { |
int l, tl, t; |
|
l = bc->prev_dc[blk_pos - 1]; |
tl = bc->prev_dc[blk_pos - 1 - bc->prev_dc_stride]; |
t = bc->prev_dc[blk_pos - bc->prev_dc_stride]; |
|
if (FFABS(t - tl) <= FFABS(l - tl)) |
dc += l; |
else |
dc += t; |
} else { |
dc += bc->prev_dc[blk_pos - bc->prev_dc_stride]; |
} |
} else if (bx) { |
dc += bc->prev_dc[bx - 1]; |
} |
bc->prev_dc[blk_pos] = dc; |
block[0] = dc * bc->qmat[0]; |
|
while (pos < 64) { |
val = rac_get_model256_sym(c, &bc->ac_model); |
if (!val) |
return 0; |
if (val == 0xF0) { |
pos += 16; |
continue; |
} |
skip = val >> 4; |
val = val & 0xF; |
if (!val) |
return -1; |
pos += skip; |
if (pos >= 64) |
return -1; |
|
sign = rac_get_model2_sym(c, &bc->sign_model); |
if (val > 1) { |
val--; |
val = (1 << val) + rac_get_bits(c, val); |
} |
if (!sign) |
val = -val; |
|
zz_pos = ff_zigzag_direct[pos]; |
block[zz_pos] = val * bc->qmat[zz_pos]; |
pos++; |
} |
|
return pos == 64 ? 0 : -1; |
} |
|
static void decode_dct_block(RangeCoder *c, DCTBlockCoder *bc, |
uint8_t *dst, int stride, int block_size, |
int *block, int mb_x, int mb_y) |
{ |
int i, j; |
int bx, by; |
int nblocks = block_size >> 3; |
|
bx = mb_x * nblocks; |
by = mb_y * nblocks; |
|
for (j = 0; j < nblocks; j++) { |
for (i = 0; i < nblocks; i++) { |
if (decode_dct(c, bc, block, bx + i, by + j)) { |
c->got_error = 1; |
return; |
} |
ff_mss34_dct_put(dst + i * 8, stride, block); |
} |
dst += 8 * stride; |
} |
} |
|
static void decode_haar_block(RangeCoder *c, HaarBlockCoder *hc, |
uint8_t *dst, int stride, int block_size, |
int *block) |
{ |
const int hsize = block_size >> 1; |
int A, B, C, D, t1, t2, t3, t4; |
int i, j; |
|
for (j = 0; j < block_size; j++) { |
for (i = 0; i < block_size; i++) { |
if (i < hsize && j < hsize) |
block[i] = rac_get_model256_sym(c, &hc->coef_model); |
else |
block[i] = decode_coeff(c, &hc->coef_hi_model); |
block[i] *= hc->scale; |
} |
block += block_size; |
} |
block -= block_size * block_size; |
|
for (j = 0; j < hsize; j++) { |
for (i = 0; i < hsize; i++) { |
A = block[i]; |
B = block[i + hsize]; |
C = block[i + hsize * block_size]; |
D = block[i + hsize * block_size + hsize]; |
|
t1 = A - B; |
t2 = C - D; |
t3 = A + B; |
t4 = C + D; |
dst[i * 2] = av_clip_uint8(t1 - t2); |
dst[i * 2 + stride] = av_clip_uint8(t1 + t2); |
dst[i * 2 + 1] = av_clip_uint8(t3 - t4); |
dst[i * 2 + 1 + stride] = av_clip_uint8(t3 + t4); |
} |
block += block_size; |
dst += stride * 2; |
} |
} |
|
static void reset_coders(MSS3Context *ctx, int quality) |
{ |
int i, j; |
|
for (i = 0; i < 3; i++) { |
ctx->btype[i].last_type = SKIP_BLOCK; |
for (j = 0; j < 5; j++) |
model_reset(&ctx->btype[i].bt_model[j]); |
ctx->fill_coder[i].fill_val = 0; |
model_reset(&ctx->fill_coder[i].coef_model); |
model256_reset(&ctx->image_coder[i].esc_model); |
model256_reset(&ctx->image_coder[i].vec_entry_model); |
model_reset(&ctx->image_coder[i].vec_size_model); |
for (j = 0; j < 125; j++) |
model_reset(&ctx->image_coder[i].vq_model[j]); |
if (ctx->dct_coder[i].quality != quality) { |
ctx->dct_coder[i].quality = quality; |
ff_mss34_gen_quant_mat(ctx->dct_coder[i].qmat, quality, !i); |
} |
memset(ctx->dct_coder[i].prev_dc, 0, |
sizeof(*ctx->dct_coder[i].prev_dc) * |
ctx->dct_coder[i].prev_dc_stride * |
ctx->dct_coder[i].prev_dc_height); |
model_reset(&ctx->dct_coder[i].dc_model); |
model2_reset(&ctx->dct_coder[i].sign_model); |
model256_reset(&ctx->dct_coder[i].ac_model); |
if (ctx->haar_coder[i].quality != quality) { |
ctx->haar_coder[i].quality = quality; |
ctx->haar_coder[i].scale = 17 - 7 * quality / 50; |
} |
model_reset(&ctx->haar_coder[i].coef_hi_model); |
model256_reset(&ctx->haar_coder[i].coef_model); |
} |
} |
|
static av_cold void init_coders(MSS3Context *ctx) |
{ |
int i, j; |
|
for (i = 0; i < 3; i++) { |
for (j = 0; j < 5; j++) |
model_init(&ctx->btype[i].bt_model[j], 5); |
model_init(&ctx->fill_coder[i].coef_model, 12); |
model256_init(&ctx->image_coder[i].esc_model); |
model256_init(&ctx->image_coder[i].vec_entry_model); |
model_init(&ctx->image_coder[i].vec_size_model, 3); |
for (j = 0; j < 125; j++) |
model_init(&ctx->image_coder[i].vq_model[j], 5); |
model_init(&ctx->dct_coder[i].dc_model, 12); |
model256_init(&ctx->dct_coder[i].ac_model); |
model_init(&ctx->haar_coder[i].coef_hi_model, 12); |
model256_init(&ctx->haar_coder[i].coef_model); |
} |
} |
|
static int mss3_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, |
AVPacket *avpkt) |
{ |
const uint8_t *buf = avpkt->data; |
int buf_size = avpkt->size; |
MSS3Context *c = avctx->priv_data; |
RangeCoder *acoder = &c->coder; |
GetByteContext gb; |
uint8_t *dst[3]; |
int dec_width, dec_height, dec_x, dec_y, quality, keyframe; |
int x, y, i, mb_width, mb_height, blk_size, btype; |
int ret; |
|
if (buf_size < HEADER_SIZE) { |
av_log(avctx, AV_LOG_ERROR, |
"Frame should have at least %d bytes, got %d instead\n", |
HEADER_SIZE, buf_size); |
return AVERROR_INVALIDDATA; |
} |
|
bytestream2_init(&gb, buf, buf_size); |
keyframe = bytestream2_get_be32(&gb); |
if (keyframe & ~0x301) { |
av_log(avctx, AV_LOG_ERROR, "Invalid frame type %X\n", keyframe); |
return AVERROR_INVALIDDATA; |
} |
keyframe = !(keyframe & 1); |
bytestream2_skip(&gb, 6); |
dec_x = bytestream2_get_be16(&gb); |
dec_y = bytestream2_get_be16(&gb); |
dec_width = bytestream2_get_be16(&gb); |
dec_height = bytestream2_get_be16(&gb); |
|
if (dec_x + dec_width > avctx->width || |
dec_y + dec_height > avctx->height || |
(dec_width | dec_height) & 0xF) { |
av_log(avctx, AV_LOG_ERROR, "Invalid frame dimensions %dx%d +%d,%d\n", |
dec_width, dec_height, dec_x, dec_y); |
return AVERROR_INVALIDDATA; |
} |
bytestream2_skip(&gb, 4); |
quality = bytestream2_get_byte(&gb); |
if (quality < 1 || quality > 100) { |
av_log(avctx, AV_LOG_ERROR, "Invalid quality setting %d\n", quality); |
return AVERROR_INVALIDDATA; |
} |
bytestream2_skip(&gb, 4); |
|
if (keyframe && !bytestream2_get_bytes_left(&gb)) { |
av_log(avctx, AV_LOG_ERROR, "Keyframe without data found\n"); |
return AVERROR_INVALIDDATA; |
} |
if (!keyframe && c->got_error) |
return buf_size; |
c->got_error = 0; |
|
if ((ret = ff_reget_buffer(avctx, c->pic)) < 0) |
return ret; |
c->pic->key_frame = keyframe; |
c->pic->pict_type = keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P; |
if (!bytestream2_get_bytes_left(&gb)) { |
if ((ret = av_frame_ref(data, c->pic)) < 0) |
return ret; |
*got_frame = 1; |
|
return buf_size; |
} |
|
reset_coders(c, quality); |
|
rac_init(acoder, buf + HEADER_SIZE, buf_size - HEADER_SIZE); |
|
mb_width = dec_width >> 4; |
mb_height = dec_height >> 4; |
dst[0] = c->pic->data[0] + dec_x + dec_y * c->pic->linesize[0]; |
dst[1] = c->pic->data[1] + dec_x / 2 + (dec_y / 2) * c->pic->linesize[1]; |
dst[2] = c->pic->data[2] + dec_x / 2 + (dec_y / 2) * c->pic->linesize[2]; |
for (y = 0; y < mb_height; y++) { |
for (x = 0; x < mb_width; x++) { |
for (i = 0; i < 3; i++) { |
blk_size = 8 << !i; |
|
btype = decode_block_type(acoder, c->btype + i); |
switch (btype) { |
case FILL_BLOCK: |
decode_fill_block(acoder, c->fill_coder + i, |
dst[i] + x * blk_size, |
c->pic->linesize[i], blk_size); |
break; |
case IMAGE_BLOCK: |
decode_image_block(acoder, c->image_coder + i, |
dst[i] + x * blk_size, |
c->pic->linesize[i], blk_size); |
break; |
case DCT_BLOCK: |
decode_dct_block(acoder, c->dct_coder + i, |
dst[i] + x * blk_size, |
c->pic->linesize[i], blk_size, |
c->dctblock, x, y); |
break; |
case HAAR_BLOCK: |
decode_haar_block(acoder, c->haar_coder + i, |
dst[i] + x * blk_size, |
c->pic->linesize[i], blk_size, |
c->hblock); |
break; |
} |
if (c->got_error || acoder->got_error) { |
av_log(avctx, AV_LOG_ERROR, "Error decoding block %d,%d\n", |
x, y); |
c->got_error = 1; |
return AVERROR_INVALIDDATA; |
} |
} |
} |
dst[0] += c->pic->linesize[0] * 16; |
dst[1] += c->pic->linesize[1] * 8; |
dst[2] += c->pic->linesize[2] * 8; |
} |
|
if ((ret = av_frame_ref(data, c->pic)) < 0) |
return ret; |
|
*got_frame = 1; |
|
return buf_size; |
} |
|
static av_cold int mss3_decode_init(AVCodecContext *avctx) |
{ |
MSS3Context * const c = avctx->priv_data; |
int i; |
|
c->avctx = avctx; |
c->pic = av_frame_alloc(); |
if (!c->pic) |
return AVERROR(ENOMEM); |
|
if ((avctx->width & 0xF) || (avctx->height & 0xF)) { |
av_log(avctx, AV_LOG_ERROR, |
"Image dimensions should be a multiple of 16.\n"); |
return AVERROR_INVALIDDATA; |
} |
|
c->got_error = 0; |
for (i = 0; i < 3; i++) { |
int b_width = avctx->width >> (2 + !!i); |
int b_height = avctx->height >> (2 + !!i); |
c->dct_coder[i].prev_dc_stride = b_width; |
c->dct_coder[i].prev_dc_height = b_height; |
c->dct_coder[i].prev_dc = av_malloc(sizeof(*c->dct_coder[i].prev_dc) * |
b_width * b_height); |
if (!c->dct_coder[i].prev_dc) { |
av_log(avctx, AV_LOG_ERROR, "Cannot allocate buffer\n"); |
av_frame_free(&c->pic); |
while (i >= 0) { |
av_freep(&c->dct_coder[i].prev_dc); |
i--; |
} |
return AVERROR(ENOMEM); |
} |
} |
|
avctx->pix_fmt = AV_PIX_FMT_YUV420P; |
|
init_coders(c); |
|
return 0; |
} |
|
static av_cold int mss3_decode_end(AVCodecContext *avctx) |
{ |
MSS3Context * const c = avctx->priv_data; |
int i; |
|
av_frame_free(&c->pic); |
for (i = 0; i < 3; i++) |
av_freep(&c->dct_coder[i].prev_dc); |
|
return 0; |
} |
|
AVCodec ff_msa1_decoder = { |
.name = "msa1", |
.long_name = NULL_IF_CONFIG_SMALL("MS ATC Screen"), |
.type = AVMEDIA_TYPE_VIDEO, |
.id = AV_CODEC_ID_MSA1, |
.priv_data_size = sizeof(MSS3Context), |
.init = mss3_decode_init, |
.close = mss3_decode_end, |
.decode = mss3_decode_frame, |
.capabilities = CODEC_CAP_DR1, |
}; |