0,0 → 1,744 |
/* |
* Lagarith lossless decoder |
* Copyright (c) 2009 Nathan Caldwell <saintdev (at) gmail.com> |
* |
* 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 |
* Lagarith lossless decoder |
* @author Nathan Caldwell |
*/ |
|
#include "avcodec.h" |
#include "get_bits.h" |
#include "mathops.h" |
#include "dsputil.h" |
#include "lagarithrac.h" |
#include "thread.h" |
|
enum LagarithFrameType { |
FRAME_RAW = 1, /**< uncompressed */ |
FRAME_U_RGB24 = 2, /**< unaligned RGB24 */ |
FRAME_ARITH_YUY2 = 3, /**< arithmetic coded YUY2 */ |
FRAME_ARITH_RGB24 = 4, /**< arithmetic coded RGB24 */ |
FRAME_SOLID_GRAY = 5, /**< solid grayscale color frame */ |
FRAME_SOLID_COLOR = 6, /**< solid non-grayscale color frame */ |
FRAME_OLD_ARITH_RGB = 7, /**< obsolete arithmetic coded RGB (no longer encoded by upstream since version 1.1.0) */ |
FRAME_ARITH_RGBA = 8, /**< arithmetic coded RGBA */ |
FRAME_SOLID_RGBA = 9, /**< solid RGBA color frame */ |
FRAME_ARITH_YV12 = 10, /**< arithmetic coded YV12 */ |
FRAME_REDUCED_RES = 11, /**< reduced resolution YV12 frame */ |
}; |
|
typedef struct LagarithContext { |
AVCodecContext *avctx; |
DSPContext dsp; |
int zeros; /**< number of consecutive zero bytes encountered */ |
int zeros_rem; /**< number of zero bytes remaining to output */ |
uint8_t *rgb_planes; |
int rgb_stride; |
} LagarithContext; |
|
/** |
* Compute the 52bit mantissa of 1/(double)denom. |
* This crazy format uses floats in an entropy coder and we have to match x86 |
* rounding exactly, thus ordinary floats aren't portable enough. |
* @param denom denominator |
* @return 52bit mantissa |
* @see softfloat_mul |
*/ |
static uint64_t softfloat_reciprocal(uint32_t denom) |
{ |
int shift = av_log2(denom - 1) + 1; |
uint64_t ret = (1ULL << 52) / denom; |
uint64_t err = (1ULL << 52) - ret * denom; |
ret <<= shift; |
err <<= shift; |
err += denom / 2; |
return ret + err / denom; |
} |
|
/** |
* (uint32_t)(x*f), where f has the given mantissa, and exponent 0 |
* Used in combination with softfloat_reciprocal computes x/(double)denom. |
* @param x 32bit integer factor |
* @param mantissa mantissa of f with exponent 0 |
* @return 32bit integer value (x*f) |
* @see softfloat_reciprocal |
*/ |
static uint32_t softfloat_mul(uint32_t x, uint64_t mantissa) |
{ |
uint64_t l = x * (mantissa & 0xffffffff); |
uint64_t h = x * (mantissa >> 32); |
h += l >> 32; |
l &= 0xffffffff; |
l += 1 << av_log2(h >> 21); |
h += l >> 32; |
return h >> 20; |
} |
|
static uint8_t lag_calc_zero_run(int8_t x) |
{ |
return (x << 1) ^ (x >> 7); |
} |
|
static int lag_decode_prob(GetBitContext *gb, uint32_t *value) |
{ |
static const uint8_t series[] = { 1, 2, 3, 5, 8, 13, 21 }; |
int i; |
int bit = 0; |
int bits = 0; |
int prevbit = 0; |
unsigned val; |
|
for (i = 0; i < 7; i++) { |
if (prevbit && bit) |
break; |
prevbit = bit; |
bit = get_bits1(gb); |
if (bit && !prevbit) |
bits += series[i]; |
} |
bits--; |
if (bits < 0 || bits > 31) { |
*value = 0; |
return -1; |
} else if (bits == 0) { |
*value = 0; |
return 0; |
} |
|
val = get_bits_long(gb, bits); |
val |= 1 << bits; |
|
*value = val - 1; |
|
return 0; |
} |
|
static int lag_read_prob_header(lag_rac *rac, GetBitContext *gb) |
{ |
int i, j, scale_factor; |
unsigned prob, cumulative_target; |
unsigned cumul_prob = 0; |
unsigned scaled_cumul_prob = 0; |
|
rac->prob[0] = 0; |
rac->prob[257] = UINT_MAX; |
/* Read probabilities from bitstream */ |
for (i = 1; i < 257; i++) { |
if (lag_decode_prob(gb, &rac->prob[i]) < 0) { |
av_log(rac->avctx, AV_LOG_ERROR, "Invalid probability encountered.\n"); |
return -1; |
} |
if ((uint64_t)cumul_prob + rac->prob[i] > UINT_MAX) { |
av_log(rac->avctx, AV_LOG_ERROR, "Integer overflow encountered in cumulative probability calculation.\n"); |
return -1; |
} |
cumul_prob += rac->prob[i]; |
if (!rac->prob[i]) { |
if (lag_decode_prob(gb, &prob)) { |
av_log(rac->avctx, AV_LOG_ERROR, "Invalid probability run encountered.\n"); |
return -1; |
} |
if (prob > 256 - i) |
prob = 256 - i; |
for (j = 0; j < prob; j++) |
rac->prob[++i] = 0; |
} |
} |
|
if (!cumul_prob) { |
av_log(rac->avctx, AV_LOG_ERROR, "All probabilities are 0!\n"); |
return -1; |
} |
|
/* Scale probabilities so cumulative probability is an even power of 2. */ |
scale_factor = av_log2(cumul_prob); |
|
if (cumul_prob & (cumul_prob - 1)) { |
uint64_t mul = softfloat_reciprocal(cumul_prob); |
for (i = 1; i <= 128; i++) { |
rac->prob[i] = softfloat_mul(rac->prob[i], mul); |
scaled_cumul_prob += rac->prob[i]; |
} |
if (scaled_cumul_prob <= 0) { |
av_log(rac->avctx, AV_LOG_ERROR, "Scaled probabilities invalid\n"); |
return AVERROR_INVALIDDATA; |
} |
for (; i < 257; i++) { |
rac->prob[i] = softfloat_mul(rac->prob[i], mul); |
scaled_cumul_prob += rac->prob[i]; |
} |
|
scale_factor++; |
cumulative_target = 1 << scale_factor; |
|
if (scaled_cumul_prob > cumulative_target) { |
av_log(rac->avctx, AV_LOG_ERROR, |
"Scaled probabilities are larger than target!\n"); |
return -1; |
} |
|
scaled_cumul_prob = cumulative_target - scaled_cumul_prob; |
|
for (i = 1; scaled_cumul_prob; i = (i & 0x7f) + 1) { |
if (rac->prob[i]) { |
rac->prob[i]++; |
scaled_cumul_prob--; |
} |
/* Comment from reference source: |
* if (b & 0x80 == 0) { // order of operations is 'wrong'; it has been left this way |
* // since the compression change is negligible and fixing it |
* // breaks backwards compatibility |
* b =- (signed int)b; |
* b &= 0xFF; |
* } else { |
* b++; |
* b &= 0x7f; |
* } |
*/ |
} |
} |
|
rac->scale = scale_factor; |
|
/* Fill probability array with cumulative probability for each symbol. */ |
for (i = 1; i < 257; i++) |
rac->prob[i] += rac->prob[i - 1]; |
|
return 0; |
} |
|
static void add_lag_median_prediction(uint8_t *dst, uint8_t *src1, |
uint8_t *diff, int w, int *left, |
int *left_top) |
{ |
/* This is almost identical to add_hfyu_median_prediction in dsputil.h. |
* However the &0xFF on the gradient predictor yealds incorrect output |
* for lagarith. |
*/ |
int i; |
uint8_t l, lt; |
|
l = *left; |
lt = *left_top; |
|
for (i = 0; i < w; i++) { |
l = mid_pred(l, src1[i], l + src1[i] - lt) + diff[i]; |
lt = src1[i]; |
dst[i] = l; |
} |
|
*left = l; |
*left_top = lt; |
} |
|
static void lag_pred_line(LagarithContext *l, uint8_t *buf, |
int width, int stride, int line) |
{ |
int L, TL; |
|
if (!line) { |
/* Left prediction only for first line */ |
L = l->dsp.add_hfyu_left_prediction(buf, buf, |
width, 0); |
} else { |
/* Left pixel is actually prev_row[width] */ |
L = buf[width - stride - 1]; |
|
if (line == 1) { |
/* Second line, left predict first pixel, the rest of the line is median predicted |
* NOTE: In the case of RGB this pixel is top predicted */ |
TL = l->avctx->pix_fmt == AV_PIX_FMT_YUV420P ? buf[-stride] : L; |
} else { |
/* Top left is 2 rows back, last pixel */ |
TL = buf[width - (2 * stride) - 1]; |
} |
|
add_lag_median_prediction(buf, buf - stride, buf, |
width, &L, &TL); |
} |
} |
|
static void lag_pred_line_yuy2(LagarithContext *l, uint8_t *buf, |
int width, int stride, int line, |
int is_luma) |
{ |
int L, TL; |
|
if (!line) { |
L= buf[0]; |
if (is_luma) |
buf[0] = 0; |
l->dsp.add_hfyu_left_prediction(buf, buf, width, 0); |
if (is_luma) |
buf[0] = L; |
return; |
} |
if (line == 1) { |
const int HEAD = is_luma ? 4 : 2; |
int i; |
|
L = buf[width - stride - 1]; |
TL = buf[HEAD - stride - 1]; |
for (i = 0; i < HEAD; i++) { |
L += buf[i]; |
buf[i] = L; |
} |
for (; i<width; i++) { |
L = mid_pred(L&0xFF, buf[i-stride], (L + buf[i-stride] - TL)&0xFF) + buf[i]; |
TL = buf[i-stride]; |
buf[i]= L; |
} |
} else { |
TL = buf[width - (2 * stride) - 1]; |
L = buf[width - stride - 1]; |
l->dsp.add_hfyu_median_prediction(buf, buf - stride, buf, width, |
&L, &TL); |
} |
} |
|
static int lag_decode_line(LagarithContext *l, lag_rac *rac, |
uint8_t *dst, int width, int stride, |
int esc_count) |
{ |
int i = 0; |
int ret = 0; |
|
if (!esc_count) |
esc_count = -1; |
|
/* Output any zeros remaining from the previous run */ |
handle_zeros: |
if (l->zeros_rem) { |
int count = FFMIN(l->zeros_rem, width - i); |
memset(dst + i, 0, count); |
i += count; |
l->zeros_rem -= count; |
} |
|
while (i < width) { |
dst[i] = lag_get_rac(rac); |
ret++; |
|
if (dst[i]) |
l->zeros = 0; |
else |
l->zeros++; |
|
i++; |
if (l->zeros == esc_count) { |
int index = lag_get_rac(rac); |
ret++; |
|
l->zeros = 0; |
|
l->zeros_rem = lag_calc_zero_run(index); |
goto handle_zeros; |
} |
} |
return ret; |
} |
|
static int lag_decode_zero_run_line(LagarithContext *l, uint8_t *dst, |
const uint8_t *src, const uint8_t *src_end, |
int width, int esc_count) |
{ |
int i = 0; |
int count; |
uint8_t zero_run = 0; |
const uint8_t *src_start = src; |
uint8_t mask1 = -(esc_count < 2); |
uint8_t mask2 = -(esc_count < 3); |
uint8_t *end = dst + (width - 2); |
|
output_zeros: |
if (l->zeros_rem) { |
count = FFMIN(l->zeros_rem, width - i); |
if (end - dst < count) { |
av_log(l->avctx, AV_LOG_ERROR, "Too many zeros remaining.\n"); |
return AVERROR_INVALIDDATA; |
} |
|
memset(dst, 0, count); |
l->zeros_rem -= count; |
dst += count; |
} |
|
while (dst < end) { |
i = 0; |
while (!zero_run && dst + i < end) { |
i++; |
if (i+2 >= src_end - src) |
return AVERROR_INVALIDDATA; |
zero_run = |
!(src[i] | (src[i + 1] & mask1) | (src[i + 2] & mask2)); |
} |
if (zero_run) { |
zero_run = 0; |
i += esc_count; |
memcpy(dst, src, i); |
dst += i; |
l->zeros_rem = lag_calc_zero_run(src[i]); |
|
src += i + 1; |
goto output_zeros; |
} else { |
memcpy(dst, src, i); |
src += i; |
dst += i; |
} |
} |
return src - src_start; |
} |
|
|
|
static int lag_decode_arith_plane(LagarithContext *l, uint8_t *dst, |
int width, int height, int stride, |
const uint8_t *src, int src_size) |
{ |
int i = 0; |
int read = 0; |
uint32_t length; |
uint32_t offset = 1; |
int esc_count; |
GetBitContext gb; |
lag_rac rac; |
const uint8_t *src_end = src + src_size; |
|
rac.avctx = l->avctx; |
l->zeros = 0; |
|
if(src_size < 2) |
return AVERROR_INVALIDDATA; |
|
esc_count = src[0]; |
if (esc_count < 4) { |
length = width * height; |
if(src_size < 5) |
return AVERROR_INVALIDDATA; |
if (esc_count && AV_RL32(src + 1) < length) { |
length = AV_RL32(src + 1); |
offset += 4; |
} |
|
init_get_bits(&gb, src + offset, src_size * 8); |
|
if (lag_read_prob_header(&rac, &gb) < 0) |
return -1; |
|
ff_lag_rac_init(&rac, &gb, length - stride); |
|
for (i = 0; i < height; i++) |
read += lag_decode_line(l, &rac, dst + (i * stride), width, |
stride, esc_count); |
|
if (read > length) |
av_log(l->avctx, AV_LOG_WARNING, |
"Output more bytes than length (%d of %d)\n", read, |
length); |
} else if (esc_count < 8) { |
esc_count -= 4; |
if (esc_count > 0) { |
/* Zero run coding only, no range coding. */ |
for (i = 0; i < height; i++) { |
int res = lag_decode_zero_run_line(l, dst + (i * stride), src, |
src_end, width, esc_count); |
if (res < 0) |
return res; |
src += res; |
} |
} else { |
if (src_size < width * height) |
return AVERROR_INVALIDDATA; // buffer not big enough |
/* Plane is stored uncompressed */ |
for (i = 0; i < height; i++) { |
memcpy(dst + (i * stride), src, width); |
src += width; |
} |
} |
} else if (esc_count == 0xff) { |
/* Plane is a solid run of given value */ |
for (i = 0; i < height; i++) |
memset(dst + i * stride, src[1], width); |
/* Do not apply prediction. |
Note: memset to 0 above, setting first value to src[1] |
and applying prediction gives the same result. */ |
return 0; |
} else { |
av_log(l->avctx, AV_LOG_ERROR, |
"Invalid zero run escape code! (%#x)\n", esc_count); |
return -1; |
} |
|
if (l->avctx->pix_fmt != AV_PIX_FMT_YUV422P) { |
for (i = 0; i < height; i++) { |
lag_pred_line(l, dst, width, stride, i); |
dst += stride; |
} |
} else { |
for (i = 0; i < height; i++) { |
lag_pred_line_yuy2(l, dst, width, stride, i, |
width == l->avctx->width); |
dst += stride; |
} |
} |
|
return 0; |
} |
|
/** |
* Decode a frame. |
* @param avctx codec context |
* @param data output AVFrame |
* @param data_size size of output data or 0 if no picture is returned |
* @param avpkt input packet |
* @return number of consumed bytes on success or negative if decode fails |
*/ |
static int lag_decode_frame(AVCodecContext *avctx, |
void *data, int *got_frame, AVPacket *avpkt) |
{ |
const uint8_t *buf = avpkt->data; |
unsigned int buf_size = avpkt->size; |
LagarithContext *l = avctx->priv_data; |
ThreadFrame frame = { .f = data }; |
AVFrame *const p = data; |
uint8_t frametype = 0; |
uint32_t offset_gu = 0, offset_bv = 0, offset_ry = 9; |
uint32_t offs[4]; |
uint8_t *srcs[4], *dst; |
int i, j, planes = 3; |
int ret; |
|
p->key_frame = 1; |
|
frametype = buf[0]; |
|
offset_gu = AV_RL32(buf + 1); |
offset_bv = AV_RL32(buf + 5); |
|
switch (frametype) { |
case FRAME_SOLID_RGBA: |
avctx->pix_fmt = AV_PIX_FMT_RGB32; |
case FRAME_SOLID_GRAY: |
if (frametype == FRAME_SOLID_GRAY) |
if (avctx->bits_per_coded_sample == 24) { |
avctx->pix_fmt = AV_PIX_FMT_RGB24; |
} else { |
avctx->pix_fmt = AV_PIX_FMT_0RGB32; |
planes = 4; |
} |
|
if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0) |
return ret; |
|
dst = p->data[0]; |
if (frametype == FRAME_SOLID_RGBA) { |
for (j = 0; j < avctx->height; j++) { |
for (i = 0; i < avctx->width; i++) |
AV_WN32(dst + i * 4, offset_gu); |
dst += p->linesize[0]; |
} |
} else { |
for (j = 0; j < avctx->height; j++) { |
memset(dst, buf[1], avctx->width * planes); |
dst += p->linesize[0]; |
} |
} |
break; |
case FRAME_SOLID_COLOR: |
if (avctx->bits_per_coded_sample == 24) { |
avctx->pix_fmt = AV_PIX_FMT_RGB24; |
} else { |
avctx->pix_fmt = AV_PIX_FMT_RGB32; |
offset_gu |= 0xFFU << 24; |
} |
|
if ((ret = ff_thread_get_buffer(avctx, &frame,0)) < 0) |
return ret; |
|
dst = p->data[0]; |
for (j = 0; j < avctx->height; j++) { |
for (i = 0; i < avctx->width; i++) |
if (avctx->bits_per_coded_sample == 24) { |
AV_WB24(dst + i * 3, offset_gu); |
} else { |
AV_WN32(dst + i * 4, offset_gu); |
} |
dst += p->linesize[0]; |
} |
break; |
case FRAME_ARITH_RGBA: |
avctx->pix_fmt = AV_PIX_FMT_RGB32; |
planes = 4; |
offset_ry += 4; |
offs[3] = AV_RL32(buf + 9); |
case FRAME_ARITH_RGB24: |
case FRAME_U_RGB24: |
if (frametype == FRAME_ARITH_RGB24 || frametype == FRAME_U_RGB24) |
avctx->pix_fmt = AV_PIX_FMT_RGB24; |
|
if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0) |
return ret; |
|
offs[0] = offset_bv; |
offs[1] = offset_gu; |
offs[2] = offset_ry; |
|
if (!l->rgb_planes) { |
l->rgb_stride = FFALIGN(avctx->width, 16); |
l->rgb_planes = av_malloc(l->rgb_stride * avctx->height * 4 + 16); |
if (!l->rgb_planes) { |
av_log(avctx, AV_LOG_ERROR, "cannot allocate temporary buffer\n"); |
return AVERROR(ENOMEM); |
} |
} |
for (i = 0; i < planes; i++) |
srcs[i] = l->rgb_planes + (i + 1) * l->rgb_stride * avctx->height - l->rgb_stride; |
for (i = 0; i < planes; i++) |
if (buf_size <= offs[i]) { |
av_log(avctx, AV_LOG_ERROR, |
"Invalid frame offsets\n"); |
return AVERROR_INVALIDDATA; |
} |
|
for (i = 0; i < planes; i++) |
lag_decode_arith_plane(l, srcs[i], |
avctx->width, avctx->height, |
-l->rgb_stride, buf + offs[i], |
buf_size - offs[i]); |
dst = p->data[0]; |
for (i = 0; i < planes; i++) |
srcs[i] = l->rgb_planes + i * l->rgb_stride * avctx->height; |
for (j = 0; j < avctx->height; j++) { |
for (i = 0; i < avctx->width; i++) { |
uint8_t r, g, b, a; |
r = srcs[0][i]; |
g = srcs[1][i]; |
b = srcs[2][i]; |
r += g; |
b += g; |
if (frametype == FRAME_ARITH_RGBA) { |
a = srcs[3][i]; |
AV_WN32(dst + i * 4, MKBETAG(a, r, g, b)); |
} else { |
dst[i * 3 + 0] = r; |
dst[i * 3 + 1] = g; |
dst[i * 3 + 2] = b; |
} |
} |
dst += p->linesize[0]; |
for (i = 0; i < planes; i++) |
srcs[i] += l->rgb_stride; |
} |
break; |
case FRAME_ARITH_YUY2: |
avctx->pix_fmt = AV_PIX_FMT_YUV422P; |
|
if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0) |
return ret; |
|
if (offset_ry >= buf_size || |
offset_gu >= buf_size || |
offset_bv >= buf_size) { |
av_log(avctx, AV_LOG_ERROR, |
"Invalid frame offsets\n"); |
return AVERROR_INVALIDDATA; |
} |
|
lag_decode_arith_plane(l, p->data[0], avctx->width, avctx->height, |
p->linesize[0], buf + offset_ry, |
buf_size - offset_ry); |
lag_decode_arith_plane(l, p->data[1], avctx->width / 2, |
avctx->height, p->linesize[1], |
buf + offset_gu, buf_size - offset_gu); |
lag_decode_arith_plane(l, p->data[2], avctx->width / 2, |
avctx->height, p->linesize[2], |
buf + offset_bv, buf_size - offset_bv); |
break; |
case FRAME_ARITH_YV12: |
avctx->pix_fmt = AV_PIX_FMT_YUV420P; |
|
if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0) |
return ret; |
if (buf_size <= offset_ry || buf_size <= offset_gu || buf_size <= offset_bv) { |
return AVERROR_INVALIDDATA; |
} |
|
if (offset_ry >= buf_size || |
offset_gu >= buf_size || |
offset_bv >= buf_size) { |
av_log(avctx, AV_LOG_ERROR, |
"Invalid frame offsets\n"); |
return AVERROR_INVALIDDATA; |
} |
|
lag_decode_arith_plane(l, p->data[0], avctx->width, avctx->height, |
p->linesize[0], buf + offset_ry, |
buf_size - offset_ry); |
lag_decode_arith_plane(l, p->data[2], avctx->width / 2, |
avctx->height / 2, p->linesize[2], |
buf + offset_gu, buf_size - offset_gu); |
lag_decode_arith_plane(l, p->data[1], avctx->width / 2, |
avctx->height / 2, p->linesize[1], |
buf + offset_bv, buf_size - offset_bv); |
break; |
default: |
av_log(avctx, AV_LOG_ERROR, |
"Unsupported Lagarith frame type: %#x\n", frametype); |
return AVERROR_PATCHWELCOME; |
} |
|
*got_frame = 1; |
|
return buf_size; |
} |
|
static av_cold int lag_decode_init(AVCodecContext *avctx) |
{ |
LagarithContext *l = avctx->priv_data; |
l->avctx = avctx; |
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ff_dsputil_init(&l->dsp, avctx); |
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return 0; |
} |
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static av_cold int lag_decode_end(AVCodecContext *avctx) |
{ |
LagarithContext *l = avctx->priv_data; |
|
av_freep(&l->rgb_planes); |
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return 0; |
} |
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AVCodec ff_lagarith_decoder = { |
.name = "lagarith", |
.long_name = NULL_IF_CONFIG_SMALL("Lagarith lossless"), |
.type = AVMEDIA_TYPE_VIDEO, |
.id = AV_CODEC_ID_LAGARITH, |
.priv_data_size = sizeof(LagarithContext), |
.init = lag_decode_init, |
.close = lag_decode_end, |
.decode = lag_decode_frame, |
.capabilities = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS, |
}; |