diff options
Diffstat (limited to 'libavcodec/scpr.c')
-rw-r--r-- | libavcodec/scpr.c | 922 |
1 files changed, 922 insertions, 0 deletions
diff --git a/libavcodec/scpr.c b/libavcodec/scpr.c new file mode 100644 index 0000000000..81597aa4dc --- /dev/null +++ b/libavcodec/scpr.c @@ -0,0 +1,922 @@ +/* + * ScreenPressor decoder + * + * Copyright (c) 2017 Paul B Mahol + * + * 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 + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "avcodec.h" +#include "bytestream.h" +#include "internal.h" + +#define TOP 0x01000000 +#define BOT 0x010000 + +typedef struct RangeCoder { + unsigned code; + unsigned range; + unsigned code1; +} RangeCoder; + +typedef struct PixelModel { + unsigned freq[256]; + unsigned lookup[16]; + unsigned total_freq; +} PixelModel; + +typedef struct SCPRContext { + AVFrame *last_frame; + AVFrame *current_frame; + GetByteContext gb; + RangeCoder rc; + PixelModel pixel_model[3][4096]; + unsigned op_model[6][7]; + unsigned run_model[6][257]; + unsigned range_model[257]; + unsigned count_model[257]; + unsigned fill_model[6]; + unsigned sxy_model[4][17]; + unsigned mv_model[2][513]; + unsigned nbx, nby; + unsigned nbcount; + unsigned *blocks; + unsigned cbits; + int cxshift; + + int (*get_freq)(RangeCoder *rc, unsigned total_freq, unsigned *freq); + int (*decode)(GetByteContext *gb, RangeCoder *rc, unsigned cumFreq, unsigned freq, unsigned total_freq); +} SCPRContext; + +static void init_rangecoder(RangeCoder *rc, GetByteContext *gb) +{ + rc->code1 = 0; + rc->range = 0xFFFFFFFFU; + rc->code = bytestream2_get_be32(gb); +} + +static void reinit_tables(SCPRContext *s) +{ + int comp, i, j; + + for (comp = 0; comp < 3; comp++) { + for (j = 0; j < 4096; j++) { + if (s->pixel_model[comp][j].total_freq != 256) { + for (i = 0; i < 256; i++) + s->pixel_model[comp][j].freq[i] = 1; + for (i = 0; i < 16; i++) + s->pixel_model[comp][j].lookup[i] = 16; + s->pixel_model[comp][j].total_freq = 256; + } + } + } + + for (j = 0; j < 6; j++) { + unsigned *p = s->run_model[j]; + for (i = 0; i < 256; i++) + p[i] = 1; + p[256] = 256; + } + + for (j = 0; j < 6; j++) { + unsigned *op = s->op_model[j]; + for (i = 0; i < 6; i++) + op[i] = 1; + op[6] = 6; + } + + for (i = 0; i < 256; i++) { + s->range_model[i] = 1; + s->count_model[i] = 1; + } + s->range_model[256] = 256; + s->count_model[256] = 256; + + for (i = 0; i < 5; i++) { + s->fill_model[i] = 1; + } + s->fill_model[5] = 5; + + for (j = 0; j < 4; j++) { + for (i = 0; i < 16; i++) { + s->sxy_model[j][i] = 1; + } + s->sxy_model[j][16] = 16; + } + + for (i = 0; i < 512; i++) { + s->mv_model[0][i] = 1; + s->mv_model[1][i] = 1; + } + s->mv_model[0][512] = 512; + s->mv_model[1][512] = 512; +} + +static int decode(GetByteContext *gb, RangeCoder *rc, unsigned cumFreq, unsigned freq, unsigned total_freq) +{ + rc->code -= cumFreq * rc->range; + rc->range *= freq; + + while (rc->range < TOP && bytestream2_get_bytes_left(gb) > 0) { + unsigned byte = bytestream2_get_byteu(gb); + rc->code = (rc->code << 8) | byte; + rc->range <<= 8; + } + + return 0; +} + +static int get_freq(RangeCoder *rc, unsigned total_freq, unsigned *freq) +{ + if (total_freq == 0) + return AVERROR_INVALIDDATA; + + rc->range = rc->range / total_freq; + + if (rc->range == 0) + return AVERROR_INVALIDDATA; + + *freq = rc->code / rc->range; + + return 0; +} + +static int decode0(GetByteContext *gb, RangeCoder *rc, unsigned cumFreq, unsigned freq, unsigned total_freq) +{ + unsigned t; + + if (total_freq == 0) + return AVERROR_INVALIDDATA; + + t = rc->range * (uint64_t)cumFreq / total_freq; + + rc->code1 += t + 1; + rc->range = rc->range * (uint64_t)(freq + cumFreq) / total_freq - (t + 1); + + while (rc->range < TOP && bytestream2_get_bytes_left(gb) > 0) { + unsigned byte = bytestream2_get_byteu(gb); + rc->code = (rc->code << 8) | byte; + rc->code1 <<= 8; + rc->range <<= 8; + } + + return 0; +} + +static int get_freq0(RangeCoder *rc, unsigned total_freq, unsigned *freq) +{ + if (rc->range == 0) + return AVERROR_INVALIDDATA; + + *freq = total_freq * (uint64_t)(rc->code - rc->code1) / rc->range; + + return 0; +} + +static int decode_value(SCPRContext *s, unsigned *cnt, unsigned maxc, unsigned step, unsigned *rval) +{ + GetByteContext *gb = &s->gb; + RangeCoder *rc = &s->rc; + unsigned totfr = cnt[maxc]; + unsigned value; + unsigned c = 0, cumfr = 0, cnt_c = 0; + int i, ret; + + if ((ret = s->get_freq(rc, totfr, &value)) < 0) + return ret; + + while (c < maxc) { + cnt_c = cnt[c]; + if (value >= cumfr + cnt_c) + cumfr += cnt_c; + else + break; + c++; + } + + if (c >= maxc) + return AVERROR_INVALIDDATA; + + if ((ret = s->decode(gb, rc, cumfr, cnt_c, totfr)) < 0) + return ret; + + cnt[c] = cnt_c + step; + totfr += step; + if (totfr > BOT) { + totfr = 0; + for (i = 0; i < maxc; i++) { + unsigned nc = (cnt[i] >> 1) + 1; + cnt[i] = nc; + totfr += nc; + } + } + + cnt[maxc] = totfr; + *rval = c; + + return 0; +} + +static int decode_unit(SCPRContext *s, PixelModel *pixel, unsigned step, unsigned *rval) +{ + GetByteContext *gb = &s->gb; + RangeCoder *rc = &s->rc; + unsigned totfr = pixel->total_freq; + unsigned value, x = 0, cumfr = 0, cnt_x = 0; + int i, j, ret, c, cnt_c; + + if ((ret = s->get_freq(rc, totfr, &value)) < 0) + return ret; + + while (x < 16) { + cnt_x = pixel->lookup[x]; + if (value >= cumfr + cnt_x) + cumfr += cnt_x; + else + break; + x++; + } + + c = x * 16; + cnt_c = 0; + while (c < 256) { + cnt_c = pixel->freq[c]; + if (value >= cumfr + cnt_c) + cumfr += cnt_c; + else + break; + c++; + } + if (x >= 16 || c >= 256) { + return AVERROR_INVALIDDATA; + } + + if ((ret = s->decode(gb, rc, cumfr, cnt_c, totfr)) < 0) + return ret; + + pixel->freq[c] = cnt_c + step; + pixel->lookup[x] = cnt_x + step; + totfr += step; + if (totfr > BOT) { + totfr = 0; + for (i = 0; i < 256; i++) { + unsigned nc = (pixel->freq[i] >> 1) + 1; + pixel->freq[i] = nc; + totfr += nc; + } + for (i = 0; i < 16; i++) { + unsigned sum = 0; + unsigned i16_17 = i << 4; + for (j = 0; j < 16; j++) + sum += pixel->freq[i16_17 + j]; + pixel->lookup[i] = sum; + } + } + pixel->total_freq = totfr; + + *rval = c & s->cbits; + + return 0; +} + +static int decode_units(SCPRContext *s, unsigned *r, unsigned *g, unsigned *b, + int *cx, int *cx1) +{ + const int cxshift = s->cxshift; + int ret; + + ret = decode_unit(s, &s->pixel_model[0][*cx + *cx1], 400, r); + if (ret < 0) + return ret; + + *cx1 = (*cx << 6) & 0xFC0; + *cx = *r >> cxshift; + ret = decode_unit(s, &s->pixel_model[1][*cx + *cx1], 400, g); + if (ret < 0) + return ret; + + *cx1 = (*cx << 6) & 0xFC0; + *cx = *g >> cxshift; + ret = decode_unit(s, &s->pixel_model[2][*cx + *cx1], 400, b); + if (ret < 0) + return ret; + + *cx1 = (*cx << 6) & 0xFC0; + *cx = *b >> cxshift; + + return 0; +} + +static int decompress_i(AVCodecContext *avctx, uint32_t *dst, int linesize) +{ + SCPRContext *s = avctx->priv_data; + GetByteContext *gb = &s->gb; + int cx = 0, cx1 = 0, k = 0, clr = 0; + int run, off, y = 0, x = 0, z, ret; + unsigned r, g, b, backstep = linesize - avctx->width; + unsigned lx, ly, ptype; + + reinit_tables(s); + bytestream2_skip(gb, 2); + init_rangecoder(&s->rc, gb); + + while (k < avctx->width + 1) { + ret = decode_units(s, &r, &g, &b, &cx, &cx1); + if (ret < 0) + return ret; + + ret = decode_value(s, s->run_model[0], 256, 400, &run); + if (ret < 0) + return ret; + if (run <= 0) + return AVERROR_INVALIDDATA; + + clr = (b << 16) + (g << 8) + r; + k += run; + while (run-- > 0) { + if (y >= avctx->height) + return AVERROR_INVALIDDATA; + + dst[y * linesize + x] = clr; + lx = x; + ly = y; + x++; + if (x >= avctx->width) { + x = 0; + y++; + } + } + } + off = -linesize - 1; + ptype = 0; + + while (x < avctx->width && y < avctx->height) { + ret = decode_value(s, s->op_model[ptype], 6, 1000, &ptype); + if (ret < 0) + return ret; + if (ptype == 0) { + ret = decode_units(s, &r, &g, &b, &cx, &cx1); + if (ret < 0) + return ret; + + clr = (b << 16) + (g << 8) + r; + } + if (ptype > 5) + return AVERROR_INVALIDDATA; + ret = decode_value(s, s->run_model[ptype], 256, 400, &run); + if (ret < 0) + return ret; + if (run <= 0) + return AVERROR_INVALIDDATA; + + switch (ptype) { + case 0: + while (run-- > 0) { + if (y >= avctx->height) + return AVERROR_INVALIDDATA; + + dst[y * linesize + x] = clr; + lx = x; + ly = y; + x++; + if (x >= avctx->width) { + x = 0; + y++; + } + } + break; + case 1: + while (run-- > 0) { + if (y >= avctx->height) + return AVERROR_INVALIDDATA; + + dst[y * linesize + x] = dst[ly * linesize + lx]; + lx = x; + ly = y; + x++; + if (x >= avctx->width) { + x = 0; + y++; + } + } + clr = dst[ly * linesize + lx]; + break; + case 2: + while (run-- > 0) { + if (y < 1 || y >= avctx->height) + return AVERROR_INVALIDDATA; + + clr = dst[y * linesize + x + off + 1]; + dst[y * linesize + x] = clr; + lx = x; + ly = y; + x++; + if (x >= avctx->width) { + x = 0; + y++; + } + } + break; + case 4: + while (run-- > 0) { + uint8_t *odst = (uint8_t *)dst; + + if (y < 1 || y >= avctx->height || + (y == 1 && x == 0)) + return AVERROR_INVALIDDATA; + + if (x == 0) { + z = backstep; + } else { + z = 0; + } + + r = odst[(ly * linesize + lx) * 4] + + odst[((y * linesize + x) + off) * 4 + 4] - + odst[((y * linesize + x) + off - z) * 4]; + g = odst[(ly * linesize + lx) * 4 + 1] + + odst[((y * linesize + x) + off) * 4 + 5] - + odst[((y * linesize + x) + off - z) * 4 + 1]; + b = odst[(ly * linesize + lx) * 4 + 2] + + odst[((y * linesize + x) + off) * 4 + 6] - + odst[((y * linesize + x) + off - z) * 4 + 2]; + clr = ((b & 0xFF) << 16) + ((g & 0xFF) << 8) + (r & 0xFF); + dst[y * linesize + x] = clr; + lx = x; + ly = y; + x++; + if (x >= avctx->width) { + x = 0; + y++; + } + } + break; + case 5: + while (run-- > 0) { + if (y < 1 || y >= avctx->height || + (y == 1 && x == 0)) + return AVERROR_INVALIDDATA; + + if (x == 0) { + z = backstep; + } else { + z = 0; + } + + clr = dst[y * linesize + x + off - z]; + dst[y * linesize + x] = clr; + lx = x; + ly = y; + x++; + if (x >= avctx->width) { + x = 0; + y++; + } + } + break; + } + + if (avctx->bits_per_coded_sample == 16) { + cx1 = (clr & 0x3F00) >> 2; + cx = (clr & 0x3FFFFF) >> 16; + } else { + cx1 = (clr & 0xFC00) >> 4; + cx = (clr & 0xFFFFFF) >> 18; + } + } + + return 0; +} + +static int decompress_p(AVCodecContext *avctx, + uint32_t *dst, int linesize, + uint32_t *prev, int plinesize) +{ + SCPRContext *s = avctx->priv_data; + GetByteContext *gb = &s->gb; + int ret, temp, min, max, x, y, cx = 0, cx1 = 0; + int backstep = linesize - avctx->width; + + if (bytestream2_get_byte(gb) == 0) + return 0; + bytestream2_skip(gb, 1); + init_rangecoder(&s->rc, gb); + + ret = decode_value(s, s->range_model, 256, 1, &min); + ret |= decode_value(s, s->range_model, 256, 1, &temp); + min += temp << 8; + ret |= decode_value(s, s->range_model, 256, 1, &max); + ret |= decode_value(s, s->range_model, 256, 1, &temp); + if (ret < 0) + return ret; + + max += temp << 8; + if (min > max || min >= s->nbcount) + return AVERROR_INVALIDDATA; + + memset(s->blocks, 0, sizeof(*s->blocks) * s->nbcount); + + while (min <= max) { + int fill, count; + + ret = decode_value(s, s->fill_model, 5, 10, &fill); + ret |= decode_value(s, s->count_model, 256, 20, &count); + if (ret < 0) + return ret; + if (count <= 0) + return AVERROR_INVALIDDATA; + + while (min < s->nbcount && count-- > 0) { + s->blocks[min++] = fill; + } + } + + for (y = 0; y < s->nby; y++) { + for (x = 0; x < s->nbx; x++) { + int sy1 = 0, sy2 = 16, sx1 = 0, sx2 = 16; + + if (s->blocks[y * s->nbx + x] == 0) + continue; + + if (((s->blocks[y * s->nbx + x] - 1) & 1) > 0) { + ret = decode_value(s, s->sxy_model[0], 16, 100, &sx1); + ret |= decode_value(s, s->sxy_model[1], 16, 100, &sy1); + ret |= decode_value(s, s->sxy_model[2], 16, 100, &sx2); + ret |= decode_value(s, s->sxy_model[3], 16, 100, &sy2); + if (ret < 0) + return ret; + + sx2++; + sy2++; + } + if (((s->blocks[y * s->nbx + x] - 1) & 2) > 0) { + int i, j, by = y * 16, bx = x * 16; + int mvx, mvy; + + ret = decode_value(s, s->mv_model[0], 512, 100, &mvx); + ret |= decode_value(s, s->mv_model[1], 512, 100, &mvy); + if (ret < 0) + return ret; + + mvx -= 256; + mvy -= 256; + + if (by + mvy + sy1 < 0 || bx + mvx + sx1 < 0 || + by + mvy + sy1 >= avctx->height || bx + mvx + sx1 >= avctx->width) + return AVERROR_INVALIDDATA; + + for (i = 0; i < sy2 - sy1 && (by + sy1 + i) < avctx->height && (by + mvy + sy1 + i) < avctx->height; i++) { + for (j = 0; j < sx2 - sx1 && (bx + sx1 + j) < avctx->width && (bx + mvx + sx1 + j) < avctx->width; j++) { + dst[(by + i + sy1) * linesize + bx + sx1 + j] = prev[(by + mvy + sy1 + i) * plinesize + bx + sx1 + mvx + j]; + } + } + } else { + int run, z, bx = x * 16 + sx1, by = y * 16 + sy1; + unsigned r, g, b, clr, ptype = 0; + + for (; by < y * 16 + sy2 && by < avctx->height;) { + ret = decode_value(s, s->op_model[ptype], 6, 1000, &ptype); + if (ret < 0) + return ret; + if (ptype == 0) { + ret = decode_units(s, &r, &g, &b, &cx, &cx1); + if (ret < 0) + return ret; + + clr = (b << 16) + (g << 8) + r; + } + if (ptype > 5) + return AVERROR_INVALIDDATA; + ret = decode_value(s, s->run_model[ptype], 256, 400, &run); + if (ret < 0) + return ret; + if (run <= 0) + return AVERROR_INVALIDDATA; + + switch (ptype) { + case 0: + while (run-- > 0) { + if (by >= avctx->height) + return AVERROR_INVALIDDATA; + + dst[by * linesize + bx] = clr; + bx++; + if (bx >= x * 16 + sx2 || bx >= avctx->width) { + bx = x * 16 + sx1; + by++; + } + } + break; + case 1: + while (run-- > 0) { + if (bx == 0) { + if (by < 1) + return AVERROR_INVALIDDATA; + z = backstep; + } else { + z = 0; + } + + if (by >= avctx->height) + return AVERROR_INVALIDDATA; + + clr = dst[by * linesize + bx - 1 - z]; + dst[by * linesize + bx] = clr; + bx++; + if (bx >= x * 16 + sx2 || bx >= avctx->width) { + bx = x * 16 + sx1; + by++; + } + } + break; + case 2: + while (run-- > 0) { + if (by < 1 || by >= avctx->height) + return AVERROR_INVALIDDATA; + + clr = dst[(by - 1) * linesize + bx]; + dst[by * linesize + bx] = clr; + bx++; + if (bx >= x * 16 + sx2 || bx >= avctx->width) { + bx = x * 16 + sx1; + by++; + } + } + break; + case 3: + while (run-- > 0) { + if (by >= avctx->height) + return AVERROR_INVALIDDATA; + + clr = prev[by * plinesize + bx]; + dst[by * linesize + bx] = clr; + bx++; + if (bx >= x * 16 + sx2 || bx >= avctx->width) { + bx = x * 16 + sx1; + by++; + } + } + break; + case 4: + while (run-- > 0) { + uint8_t *odst = (uint8_t *)dst; + + if (by < 1 || by >= avctx->height) + return AVERROR_INVALIDDATA; + + if (bx == 0) { + if (by < 2) + return AVERROR_INVALIDDATA; + z = backstep; + } else { + z = 0; + } + + r = odst[((by - 1) * linesize + bx) * 4] + + odst[(by * linesize + bx - 1 - z) * 4] - + odst[((by - 1) * linesize + bx - 1 - z) * 4]; + g = odst[((by - 1) * linesize + bx) * 4 + 1] + + odst[(by * linesize + bx - 1 - z) * 4 + 1] - + odst[((by - 1) * linesize + bx - 1 - z) * 4 + 1]; + b = odst[((by - 1) * linesize + bx) * 4 + 2] + + odst[(by * linesize + bx - 1 - z) * 4 + 2] - + odst[((by - 1) * linesize + bx - 1 - z) * 4 + 2]; + clr = ((b & 0xFF) << 16) + ((g & 0xFF) << 8) + (r & 0xFF); + dst[by * linesize + bx] = clr; + bx++; + if (bx >= x * 16 + sx2 || bx >= avctx->width) { + bx = x * 16 + sx1; + by++; + } + } + break; + case 5: + while (run-- > 0) { + if (by < 1 || by >= avctx->height) + return AVERROR_INVALIDDATA; + + if (bx == 0) { + if (by < 2) + return AVERROR_INVALIDDATA; + z = backstep; + } else { + z = 0; + } + + clr = dst[(by - 1) * linesize + bx - 1 - z]; + dst[by * linesize + bx] = clr; + bx++; + if (bx >= x * 16 + sx2 || bx >= avctx->width) { + bx = x * 16 + sx1; + by++; + } + } + break; + } + + if (avctx->bits_per_coded_sample == 16) { + cx1 = (clr & 0x3F00) >> 2; + cx = (clr & 0x3FFFFF) >> 16; + } else { + cx1 = (clr & 0xFC00) >> 4; + cx = (clr & 0xFFFFFF) >> 18; + } + } + } + } + } + + return 0; +} + +static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, + AVPacket *avpkt) +{ + SCPRContext *s = avctx->priv_data; + GetByteContext *gb = &s->gb; + AVFrame *frame = data; + int ret, type; + + if (avctx->bits_per_coded_sample == 16) { + if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) + return ret; + } + + if ((ret = ff_reget_buffer(avctx, s->current_frame)) < 0) + return ret; + + bytestream2_init(gb, avpkt->data, avpkt->size); + + type = bytestream2_peek_byte(gb); + + if (type == 2) { + s->get_freq = get_freq0; + s->decode = decode0; + frame->key_frame = 1; + ret = decompress_i(avctx, (uint32_t *)s->current_frame->data[0], + s->current_frame->linesize[0] / 4); + } else if (type == 18) { + s->get_freq = get_freq; + s->decode = decode; + frame->key_frame = 1; + ret = decompress_i(avctx, (uint32_t *)s->current_frame->data[0], + s->current_frame->linesize[0] / 4); + } else if (type == 17) { + uint32_t clr, *dst = (uint32_t *)s->current_frame->data[0]; + int x, y; + + frame->key_frame = 1; + bytestream2_skip(gb, 1); + if (avctx->bits_per_coded_sample == 16) { + uint16_t value = bytestream2_get_le16(gb); + int r, g, b; + + r = (value ) & 31; + g = (value >> 5) & 31; + b = (value >> 10) & 31; + clr = (r << 16) + (g << 8) + b; + } else { + clr = bytestream2_get_le24(gb); + } + for (y = 0; y < avctx->height; y++) { + for (x = 0; x < avctx->width; x++) { + dst[x] = clr; + } + dst += s->current_frame->linesize[0] / 4; + } + } else if (type == 0 || type == 1) { + frame->key_frame = 0; + + ret = av_frame_copy(s->current_frame, s->last_frame); + if (ret < 0) + return ret; + + ret = decompress_p(avctx, (uint32_t *)s->current_frame->data[0], + s->current_frame->linesize[0] / 4, + (uint32_t *)s->last_frame->data[0], + s->last_frame->linesize[0] / 4); + } else { + return AVERROR_PATCHWELCOME; + } + + if (ret < 0) + return ret; + + if (avctx->bits_per_coded_sample != 16) { + ret = av_frame_ref(data, s->current_frame); + if (ret < 0) + return ret; + } else { + uint8_t *dst = frame->data[0]; + int x, y; + + ret = av_frame_copy(frame, s->current_frame); + if (ret < 0) + return ret; + + // scale up each sample by 8 + for (y = 0; y < avctx->height; y++) { + // If the image is sufficiently aligned, compute 8 samples at once + if (!(((uintptr_t)dst) & 7)) { + uint64_t *dst64 = (uint64_t *)dst; + int w = avctx->width>>1; + for (x = 0; x < w; x++) { + dst64[x] = (dst64[x] << 3) & 0xFCFCFCFCFCFCFCFCULL; + } + x *= 8; + } else + x = 0; + for (; x < avctx->width * 4; x++) { + dst[x] = dst[x] << 3; + } + dst += frame->linesize[0]; + } + } + + frame->pict_type = frame->key_frame ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P; + + FFSWAP(AVFrame *, s->current_frame, s->last_frame); + + frame->data[0] += frame->linesize[0] * (avctx->height - 1); + frame->linesize[0] *= -1; + + *got_frame = 1; + + return avpkt->size; +} + +static av_cold int decode_init(AVCodecContext *avctx) +{ + SCPRContext *s = avctx->priv_data; + + switch (avctx->bits_per_coded_sample) { + case 16: avctx->pix_fmt = AV_PIX_FMT_RGB0; break; + case 24: + case 32: avctx->pix_fmt = AV_PIX_FMT_BGR0; break; + default: + av_log(avctx, AV_LOG_ERROR, "Unsupported bitdepth %i\n", avctx->bits_per_coded_sample); + return AVERROR_INVALIDDATA; + } + + s->get_freq = get_freq0; + s->decode = decode0; + + s->cxshift = avctx->bits_per_coded_sample == 16 ? 0 : 2; + s->cbits = avctx->bits_per_coded_sample == 16 ? 0x1F : 0xFF; + s->nbx = (avctx->width + 15) / 16; + s->nby = (avctx->height + 15) / 16; + s->nbcount = s->nbx * s->nby; + s->blocks = av_malloc_array(s->nbcount, sizeof(*s->blocks)); + if (!s->blocks) + return AVERROR(ENOMEM); + + s->last_frame = av_frame_alloc(); + s->current_frame = av_frame_alloc(); + if (!s->last_frame || !s->current_frame) + return AVERROR(ENOMEM); + + return 0; +} + +static av_cold int decode_close(AVCodecContext *avctx) +{ + SCPRContext *s = avctx->priv_data; + + av_freep(&s->blocks); + av_frame_free(&s->last_frame); + av_frame_free(&s->current_frame); + + return 0; +} + +AVCodec ff_scpr_decoder = { + .name = "scpr", + .long_name = NULL_IF_CONFIG_SMALL("ScreenPressor"), + .type = AVMEDIA_TYPE_VIDEO, + .id = AV_CODEC_ID_SCPR, + .priv_data_size = sizeof(SCPRContext), + .init = decode_init, + .close = decode_close, + .decode = decode_frame, + .capabilities = AV_CODEC_CAP_DR1, + .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | + FF_CODEC_CAP_INIT_CLEANUP, +}; |