ffmpeg/libavcodec/mss2.c

859 lines
26 KiB
C

/*
* Microsoft Screen 2 (aka Windows Media Video V9 Screen) decoder
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Microsoft Screen 2 (aka Windows Media Video V9 Screen) decoder
*/
#include "libavutil/avassert.h"
#include "error_resilience.h"
#include "internal.h"
#include "mpeg_er.h"
#include "msmpeg4.h"
#include "msmpeg4data.h"
#include "qpeldsp.h"
#include "vc1.h"
#include "mss12.h"
#include "mss2dsp.h"
typedef struct MSS2Context {
VC1Context v;
int split_position;
AVFrame *last_pic;
MSS12Context c;
MSS2DSPContext dsp;
QpelDSPContext qdsp;
SliceContext sc[2];
} MSS2Context;
static void arith2_normalise(ArithCoder *c)
{
while ((c->high >> 15) - (c->low >> 15) < 2) {
if ((c->low ^ c->high) & 0x10000) {
c->high ^= 0x8000;
c->value ^= 0x8000;
c->low ^= 0x8000;
}
c->high = c->high << 8 & 0xFFFFFF | 0xFF;
c->value = c->value << 8 & 0xFFFFFF | bytestream2_get_byte(c->gbc.gB);
c->low = c->low << 8 & 0xFFFFFF;
}
}
ARITH_GET_BIT(2)
/* L. Stuiver and A. Moffat: "Piecewise Integer Mapping for Arithmetic Coding."
* In Proc. 8th Data Compression Conference (DCC '98), pp. 3-12, Mar. 1998 */
static int arith2_get_scaled_value(int value, int n, int range)
{
int split = (n << 1) - range;
if (value > split)
return split + (value - split >> 1);
else
return value;
}
static void arith2_rescale_interval(ArithCoder *c, int range,
int low, int high, int n)
{
int split = (n << 1) - range;
if (high > split)
c->high = split + (high - split << 1);
else
c->high = high;
c->high += c->low - 1;
if (low > split)
c->low += split + (low - split << 1);
else
c->low += low;
}
static int arith2_get_number(ArithCoder *c, int n)
{
int range = c->high - c->low + 1;
int scale = av_log2(range) - av_log2(n);
int val;
if (n << scale > range)
scale--;
n <<= scale;
val = arith2_get_scaled_value(c->value - c->low, n, range) >> scale;
arith2_rescale_interval(c, range, val << scale, (val + 1) << scale, n);
arith2_normalise(c);
return val;
}
static int arith2_get_prob(ArithCoder *c, int16_t *probs)
{
int range = c->high - c->low + 1, n = *probs;
int scale = av_log2(range) - av_log2(n);
int i = 0, val;
if (n << scale > range)
scale--;
n <<= scale;
val = arith2_get_scaled_value(c->value - c->low, n, range) >> scale;
while (probs[++i] > val) ;
arith2_rescale_interval(c, range,
probs[i] << scale, probs[i - 1] << scale, n);
return i;
}
ARITH_GET_MODEL_SYM(2)
static int arith2_get_consumed_bytes(ArithCoder *c)
{
int diff = (c->high >> 16) - (c->low >> 16);
int bp = bytestream2_tell(c->gbc.gB) - 3 << 3;
int bits = 1;
while (!(diff & 0x80)) {
bits++;
diff <<= 1;
}
return (bits + bp + 7 >> 3) + ((c->low >> 16) + 1 == c->high >> 16);
}
static void arith2_init(ArithCoder *c, GetByteContext *gB)
{
c->low = 0;
c->high = 0xFFFFFF;
c->value = bytestream2_get_be24(gB);
c->gbc.gB = gB;
c->get_model_sym = arith2_get_model_sym;
c->get_number = arith2_get_number;
}
static int decode_pal_v2(MSS12Context *ctx, const uint8_t *buf, int buf_size)
{
int i, ncol;
uint32_t *pal = ctx->pal + 256 - ctx->free_colours;
if (!ctx->free_colours)
return 0;
ncol = *buf++;
if (ncol > ctx->free_colours || buf_size < 2 + ncol * 3)
return AVERROR_INVALIDDATA;
for (i = 0; i < ncol; i++)
*pal++ = AV_RB24(buf + 3 * i);
return 1 + ncol * 3;
}
static int decode_555(GetByteContext *gB, uint16_t *dst, int stride,
int keyframe, int w, int h)
{
int last_symbol = 0, repeat = 0, prev_avail = 0;
if (!keyframe) {
int x, y, endx, endy, t;
#define READ_PAIR(a, b) \
a = bytestream2_get_byte(gB) << 4; \
t = bytestream2_get_byte(gB); \
a |= t >> 4; \
b = (t & 0xF) << 8; \
b |= bytestream2_get_byte(gB); \
READ_PAIR(x, endx)
READ_PAIR(y, endy)
if (endx >= w || endy >= h || x > endx || y > endy)
return AVERROR_INVALIDDATA;
dst += x + stride * y;
w = endx - x + 1;
h = endy - y + 1;
if (y)
prev_avail = 1;
}
do {
uint16_t *p = dst;
do {
if (repeat-- < 1) {
int b = bytestream2_get_byte(gB);
if (b < 128)
last_symbol = b << 8 | bytestream2_get_byte(gB);
else if (b > 129) {
repeat = 0;
while (b-- > 130)
repeat = (repeat << 8) + bytestream2_get_byte(gB) + 1;
if (last_symbol == -2) {
int skip = FFMIN((unsigned)repeat, dst + w - p);
repeat -= skip;
p += skip;
}
} else
last_symbol = 127 - b;
}
if (last_symbol >= 0)
*p = last_symbol;
else if (last_symbol == -1 && prev_avail)
*p = *(p - stride);
} while (++p < dst + w);
dst += stride;
prev_avail = 1;
} while (--h);
return 0;
}
static int decode_rle(GetBitContext *gb, uint8_t *pal_dst, int pal_stride,
uint8_t *rgb_dst, int rgb_stride, uint32_t *pal,
int keyframe, int kf_slipt, int slice, int w, int h)
{
uint8_t bits[270] = { 0 };
uint32_t codes[270];
VLC vlc;
int current_length = 0, read_codes = 0, next_code = 0, current_codes = 0;
int remaining_codes, surplus_codes, i;
const int alphabet_size = 270 - keyframe;
int last_symbol = 0, repeat = 0, prev_avail = 0;
if (!keyframe) {
int x, y, clipw, cliph;
x = get_bits(gb, 12);
y = get_bits(gb, 12);
clipw = get_bits(gb, 12) + 1;
cliph = get_bits(gb, 12) + 1;
if (x + clipw > w || y + cliph > h)
return AVERROR_INVALIDDATA;
pal_dst += pal_stride * y + x;
rgb_dst += rgb_stride * y + x * 3;
w = clipw;
h = cliph;
if (y)
prev_avail = 1;
} else {
if (slice > 0) {
pal_dst += pal_stride * kf_slipt;
rgb_dst += rgb_stride * kf_slipt;
prev_avail = 1;
h -= kf_slipt;
} else
h = kf_slipt;
}
/* read explicit codes */
do {
while (current_codes--) {
int symbol = get_bits(gb, 8);
if (symbol >= 204 - keyframe)
symbol += 14 - keyframe;
else if (symbol > 189)
symbol = get_bits1(gb) + (symbol << 1) - 190;
if (bits[symbol])
return AVERROR_INVALIDDATA;
bits[symbol] = current_length;
codes[symbol] = next_code++;
read_codes++;
}
current_length++;
next_code <<= 1;
remaining_codes = (1 << current_length) - next_code;
current_codes = get_bits(gb, av_ceil_log2(remaining_codes + 1));
if (current_length > 22 || current_codes > remaining_codes)
return AVERROR_INVALIDDATA;
} while (current_codes != remaining_codes);
remaining_codes = alphabet_size - read_codes;
/* determine the minimum length to fit the rest of the alphabet */
while ((surplus_codes = (2 << current_length) -
(next_code << 1) - remaining_codes) < 0) {
current_length++;
next_code <<= 1;
}
/* add the rest of the symbols lexicographically */
for (i = 0; i < alphabet_size; i++)
if (!bits[i]) {
if (surplus_codes-- == 0) {
current_length++;
next_code <<= 1;
}
bits[i] = current_length;
codes[i] = next_code++;
}
if (next_code != 1 << current_length)
return AVERROR_INVALIDDATA;
if (i = init_vlc(&vlc, 9, alphabet_size, bits, 1, 1, codes, 4, 4, 0))
return i;
/* frame decode */
do {
uint8_t *pp = pal_dst;
uint8_t *rp = rgb_dst;
do {
if (repeat-- < 1) {
int b = get_vlc2(gb, vlc.table, 9, 3);
if (b < 256)
last_symbol = b;
else if (b < 268) {
b -= 256;
if (b == 11)
b = get_bits(gb, 4) + 10;
if (!b)
repeat = 0;
else
repeat = get_bits(gb, b);
repeat += (1 << b) - 1;
if (last_symbol == -2) {
int skip = FFMIN(repeat, pal_dst + w - pp);
repeat -= skip;
pp += skip;
rp += skip * 3;
}
} else
last_symbol = 267 - b;
}
if (last_symbol >= 0) {
*pp = last_symbol;
AV_WB24(rp, pal[last_symbol]);
} else if (last_symbol == -1 && prev_avail) {
*pp = *(pp - pal_stride);
memcpy(rp, rp - rgb_stride, 3);
}
rp += 3;
} while (++pp < pal_dst + w);
pal_dst += pal_stride;
rgb_dst += rgb_stride;
prev_avail = 1;
} while (--h);
ff_free_vlc(&vlc);
return 0;
}
static int decode_wmv9(AVCodecContext *avctx, const uint8_t *buf, int buf_size,
int x, int y, int w, int h, int wmv9_mask)
{
MSS2Context *ctx = avctx->priv_data;
MSS12Context *c = &ctx->c;
VC1Context *v = avctx->priv_data;
MpegEncContext *s = &v->s;
AVFrame *f;
int ret;
ff_mpeg_flush(avctx);
init_get_bits(&s->gb, buf, buf_size * 8);
s->loop_filter = avctx->skip_loop_filter < AVDISCARD_ALL;
if (ff_vc1_parse_frame_header(v, &s->gb) < 0) {
av_log(v->s.avctx, AV_LOG_ERROR, "header error\n");
return AVERROR_INVALIDDATA;
}
if (s->pict_type != AV_PICTURE_TYPE_I) {
av_log(v->s.avctx, AV_LOG_ERROR, "expected I-frame\n");
return AVERROR_INVALIDDATA;
}
avctx->pix_fmt = AV_PIX_FMT_YUV420P;
if ((ret = ff_mpv_frame_start(s, avctx)) < 0) {
av_log(v->s.avctx, AV_LOG_ERROR, "ff_mpv_frame_start error\n");
avctx->pix_fmt = AV_PIX_FMT_RGB24;
return ret;
}
ff_mpeg_er_frame_start(s);
v->bits = buf_size * 8;
v->end_mb_x = (w + 15) >> 4;
s->end_mb_y = (h + 15) >> 4;
if (v->respic & 1)
v->end_mb_x = v->end_mb_x + 1 >> 1;
if (v->respic & 2)
s->end_mb_y = s->end_mb_y + 1 >> 1;
ff_vc1_decode_blocks(v);
ff_er_frame_end(&s->er);
ff_mpv_frame_end(s);
f = s->current_picture.f;
if (v->respic == 3) {
ctx->dsp.upsample_plane(f->data[0], f->linesize[0], w, h);
ctx->dsp.upsample_plane(f->data[1], f->linesize[1], w >> 1, h >> 1);
ctx->dsp.upsample_plane(f->data[2], f->linesize[2], w >> 1, h >> 1);
} else if (v->respic)
avpriv_request_sample(v->s.avctx,
"Asymmetric WMV9 rectangle subsampling");
av_assert0(f->linesize[1] == f->linesize[2]);
if (wmv9_mask != -1)
ctx->dsp.mss2_blit_wmv9_masked(c->rgb_pic + y * c->rgb_stride + x * 3,
c->rgb_stride, wmv9_mask,
c->pal_pic + y * c->pal_stride + x,
c->pal_stride,
f->data[0], f->linesize[0],
f->data[1], f->data[2], f->linesize[1],
w, h);
else
ctx->dsp.mss2_blit_wmv9(c->rgb_pic + y * c->rgb_stride + x * 3,
c->rgb_stride,
f->data[0], f->linesize[0],
f->data[1], f->data[2], f->linesize[1],
w, h);
avctx->pix_fmt = AV_PIX_FMT_RGB24;
return 0;
}
typedef struct Rectangle {
int coded, x, y, w, h;
} Rectangle;
#define MAX_WMV9_RECTANGLES 20
#define ARITH2_PADDING 2
static int mss2_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
MSS2Context *ctx = avctx->priv_data;
MSS12Context *c = &ctx->c;
AVFrame *frame = data;
GetBitContext gb;
GetByteContext gB;
ArithCoder acoder;
int keyframe, has_wmv9, has_mv, is_rle, is_555, ret;
Rectangle wmv9rects[MAX_WMV9_RECTANGLES], *r;
int used_rects = 0, i, implicit_rect = 0, av_uninit(wmv9_mask);
av_assert0(FF_INPUT_BUFFER_PADDING_SIZE >=
ARITH2_PADDING + (MIN_CACHE_BITS + 7) / 8);
init_get_bits(&gb, buf, buf_size * 8);
if (keyframe = get_bits1(&gb))
skip_bits(&gb, 7);
has_wmv9 = get_bits1(&gb);
has_mv = keyframe ? 0 : get_bits1(&gb);
is_rle = get_bits1(&gb);
is_555 = is_rle && get_bits1(&gb);
if (c->slice_split > 0)
ctx->split_position = c->slice_split;
else if (c->slice_split < 0) {
if (get_bits1(&gb)) {
if (get_bits1(&gb)) {
if (get_bits1(&gb))
ctx->split_position = get_bits(&gb, 16);
else
ctx->split_position = get_bits(&gb, 12);
} else
ctx->split_position = get_bits(&gb, 8) << 4;
} else {
if (keyframe)
ctx->split_position = avctx->height / 2;
}
} else
ctx->split_position = avctx->height;
if (c->slice_split && (ctx->split_position < 1 - is_555 ||
ctx->split_position > avctx->height - 1))
return AVERROR_INVALIDDATA;
align_get_bits(&gb);
buf += get_bits_count(&gb) >> 3;
buf_size -= get_bits_count(&gb) >> 3;
if (buf_size < 1)
return AVERROR_INVALIDDATA;
if (is_555 && (has_wmv9 || has_mv || c->slice_split && ctx->split_position))
return AVERROR_INVALIDDATA;
avctx->pix_fmt = is_555 ? AV_PIX_FMT_RGB555 : AV_PIX_FMT_RGB24;
if (ctx->last_pic->format != avctx->pix_fmt)
av_frame_unref(ctx->last_pic);
if (has_wmv9) {
bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
arith2_init(&acoder, &gB);
implicit_rect = !arith2_get_bit(&acoder);
while (arith2_get_bit(&acoder)) {
if (used_rects == MAX_WMV9_RECTANGLES)
return AVERROR_INVALIDDATA;
r = &wmv9rects[used_rects];
if (!used_rects)
r->x = arith2_get_number(&acoder, avctx->width);
else
r->x = arith2_get_number(&acoder, avctx->width -
wmv9rects[used_rects - 1].x) +
wmv9rects[used_rects - 1].x;
r->y = arith2_get_number(&acoder, avctx->height);
r->w = arith2_get_number(&acoder, avctx->width - r->x) + 1;
r->h = arith2_get_number(&acoder, avctx->height - r->y) + 1;
used_rects++;
}
if (implicit_rect && used_rects) {
av_log(avctx, AV_LOG_ERROR, "implicit_rect && used_rects > 0\n");
return AVERROR_INVALIDDATA;
}
if (implicit_rect) {
wmv9rects[0].x = 0;
wmv9rects[0].y = 0;
wmv9rects[0].w = avctx->width;
wmv9rects[0].h = avctx->height;
used_rects = 1;
}
for (i = 0; i < used_rects; i++) {
if (!implicit_rect && arith2_get_bit(&acoder)) {
av_log(avctx, AV_LOG_ERROR, "Unexpected grandchildren\n");
return AVERROR_INVALIDDATA;
}
if (!i) {
wmv9_mask = arith2_get_bit(&acoder) - 1;
if (!wmv9_mask)
wmv9_mask = arith2_get_number(&acoder, 256);
}
wmv9rects[i].coded = arith2_get_number(&acoder, 2);
}
buf += arith2_get_consumed_bytes(&acoder);
buf_size -= arith2_get_consumed_bytes(&acoder);
if (buf_size < 1)
return AVERROR_INVALIDDATA;
}
c->mvX = c->mvY = 0;
if (keyframe && !is_555) {
if ((i = decode_pal_v2(c, buf, buf_size)) < 0)
return AVERROR_INVALIDDATA;
buf += i;
buf_size -= i;
} else if (has_mv) {
buf += 4;
buf_size -= 4;
if (buf_size < 1)
return AVERROR_INVALIDDATA;
c->mvX = AV_RB16(buf - 4) - avctx->width;
c->mvY = AV_RB16(buf - 2) - avctx->height;
}
if (c->mvX < 0 || c->mvY < 0) {
FFSWAP(uint8_t *, c->pal_pic, c->last_pal_pic);
if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0) {
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return ret;
}
if (ctx->last_pic->data[0]) {
av_assert0(frame->linesize[0] == ctx->last_pic->linesize[0]);
c->last_rgb_pic = ctx->last_pic->data[0] +
ctx->last_pic->linesize[0] * (avctx->height - 1);
} else {
av_log(avctx, AV_LOG_ERROR, "Missing keyframe\n");
return AVERROR_INVALIDDATA;
}
} else {
if ((ret = ff_reget_buffer(avctx, ctx->last_pic)) < 0) {
av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
return ret;
}
if ((ret = av_frame_ref(frame, ctx->last_pic)) < 0)
return ret;
c->last_rgb_pic = NULL;
}
c->rgb_pic = frame->data[0] +
frame->linesize[0] * (avctx->height - 1);
c->rgb_stride = -frame->linesize[0];
frame->key_frame = keyframe;
frame->pict_type = keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
if (is_555) {
bytestream2_init(&gB, buf, buf_size);
if (decode_555(&gB, (uint16_t *)c->rgb_pic, c->rgb_stride >> 1,
keyframe, avctx->width, avctx->height))
return AVERROR_INVALIDDATA;
buf_size -= bytestream2_tell(&gB);
} else {
if (keyframe) {
c->corrupted = 0;
ff_mss12_slicecontext_reset(&ctx->sc[0]);
if (c->slice_split)
ff_mss12_slicecontext_reset(&ctx->sc[1]);
}
if (is_rle) {
init_get_bits(&gb, buf, buf_size * 8);
if (ret = decode_rle(&gb, c->pal_pic, c->pal_stride,
c->rgb_pic, c->rgb_stride, c->pal, keyframe,
ctx->split_position, 0,
avctx->width, avctx->height))
return ret;
align_get_bits(&gb);
if (c->slice_split)
if (ret = decode_rle(&gb, c->pal_pic, c->pal_stride,
c->rgb_pic, c->rgb_stride, c->pal, keyframe,
ctx->split_position, 1,
avctx->width, avctx->height))
return ret;
align_get_bits(&gb);
buf += get_bits_count(&gb) >> 3;
buf_size -= get_bits_count(&gb) >> 3;
} else if (!implicit_rect || wmv9_mask != -1) {
if (c->corrupted)
return AVERROR_INVALIDDATA;
bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
arith2_init(&acoder, &gB);
c->keyframe = keyframe;
if (c->corrupted = ff_mss12_decode_rect(&ctx->sc[0], &acoder, 0, 0,
avctx->width,
ctx->split_position))
return AVERROR_INVALIDDATA;
buf += arith2_get_consumed_bytes(&acoder);
buf_size -= arith2_get_consumed_bytes(&acoder);
if (c->slice_split) {
if (buf_size < 1)
return AVERROR_INVALIDDATA;
bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
arith2_init(&acoder, &gB);
if (c->corrupted = ff_mss12_decode_rect(&ctx->sc[1], &acoder, 0,
ctx->split_position,
avctx->width,
avctx->height - ctx->split_position))
return AVERROR_INVALIDDATA;
buf += arith2_get_consumed_bytes(&acoder);
buf_size -= arith2_get_consumed_bytes(&acoder);
}
} else
memset(c->pal_pic, 0, c->pal_stride * avctx->height);
}
if (has_wmv9) {
for (i = 0; i < used_rects; i++) {
int x = wmv9rects[i].x;
int y = wmv9rects[i].y;
int w = wmv9rects[i].w;
int h = wmv9rects[i].h;
if (wmv9rects[i].coded) {
int WMV9codedFrameSize;
if (buf_size < 4 || !(WMV9codedFrameSize = AV_RL24(buf)))
return AVERROR_INVALIDDATA;
if (ret = decode_wmv9(avctx, buf + 3, buf_size - 3,
x, y, w, h, wmv9_mask))
return ret;
buf += WMV9codedFrameSize + 3;
buf_size -= WMV9codedFrameSize + 3;
} else {
uint8_t *dst = c->rgb_pic + y * c->rgb_stride + x * 3;
if (wmv9_mask != -1) {
ctx->dsp.mss2_gray_fill_masked(dst, c->rgb_stride,
wmv9_mask,
c->pal_pic + y * c->pal_stride + x,
c->pal_stride,
w, h);
} else {
do {
memset(dst, 0x80, w * 3);
dst += c->rgb_stride;
} while (--h);
}
}
}
}
if (buf_size)
av_log(avctx, AV_LOG_WARNING, "buffer not fully consumed\n");
if (c->mvX < 0 || c->mvY < 0) {
av_frame_unref(ctx->last_pic);
ret = av_frame_ref(ctx->last_pic, frame);
if (ret < 0)
return ret;
}
*got_frame = 1;
return avpkt->size;
}
static av_cold int wmv9_init(AVCodecContext *avctx)
{
VC1Context *v = avctx->priv_data;
int ret;
v->s.avctx = avctx;
if ((ret = ff_vc1_init_common(v)) < 0)
return ret;
ff_vc1dsp_init(&v->vc1dsp);
v->profile = PROFILE_MAIN;
v->zz_8x4 = ff_wmv2_scantableA;
v->zz_4x8 = ff_wmv2_scantableB;
v->res_y411 = 0;
v->res_sprite = 0;
v->frmrtq_postproc = 7;
v->bitrtq_postproc = 31;
v->res_x8 = 0;
v->multires = 0;
v->res_fasttx = 1;
v->fastuvmc = 0;
v->extended_mv = 0;
v->dquant = 1;
v->vstransform = 1;
v->res_transtab = 0;
v->overlap = 0;
v->resync_marker = 0;
v->rangered = 0;
v->s.max_b_frames = avctx->max_b_frames = 0;
v->quantizer_mode = 0;
v->finterpflag = 0;
v->res_rtm_flag = 1;
ff_vc1_init_transposed_scantables(v);
if ((ret = ff_msmpeg4_decode_init(avctx)) < 0 ||
(ret = ff_vc1_decode_init_alloc_tables(v)) < 0)
return ret;
/* error concealment */
v->s.me.qpel_put = v->s.qdsp.put_qpel_pixels_tab;
v->s.me.qpel_avg = v->s.qdsp.avg_qpel_pixels_tab;
return 0;
}
static av_cold int mss2_decode_end(AVCodecContext *avctx)
{
MSS2Context *const ctx = avctx->priv_data;
av_frame_free(&ctx->last_pic);
ff_mss12_decode_end(&ctx->c);
av_freep(&ctx->c.pal_pic);
av_freep(&ctx->c.last_pal_pic);
ff_vc1_decode_end(avctx);
return 0;
}
static av_cold int mss2_decode_init(AVCodecContext *avctx)
{
MSS2Context * const ctx = avctx->priv_data;
MSS12Context *c = &ctx->c;
int ret;
c->avctx = avctx;
if (ret = ff_mss12_decode_init(c, 1, &ctx->sc[0], &ctx->sc[1]))
return ret;
c->pal_stride = c->mask_stride;
c->pal_pic = av_mallocz(c->pal_stride * avctx->height);
c->last_pal_pic = av_mallocz(c->pal_stride * avctx->height);
if (!c->pal_pic || !c->last_pal_pic) {
mss2_decode_end(avctx);
return AVERROR(ENOMEM);
}
if (ret = wmv9_init(avctx)) {
mss2_decode_end(avctx);
return ret;
}
ff_mss2dsp_init(&ctx->dsp);
ff_qpeldsp_init(&ctx->qdsp);
avctx->pix_fmt = c->free_colours == 127 ? AV_PIX_FMT_RGB555
: AV_PIX_FMT_RGB24;
ctx->last_pic = av_frame_alloc();
if (!ctx->last_pic) {
mss2_decode_end(avctx);
return AVERROR(ENOMEM);
}
return 0;
}
AVCodec ff_mss2_decoder = {
.name = "mss2",
.long_name = NULL_IF_CONFIG_SMALL("MS Windows Media Video V9 Screen"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_MSS2,
.priv_data_size = sizeof(MSS2Context),
.init = mss2_decode_init,
.close = mss2_decode_end,
.decode = mss2_decode_frame,
.capabilities = CODEC_CAP_DR1,
};