/* * Escape 130 video decoder * Copyright (C) 2008 Eli Friedman (eli.friedman <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 */ #include "libavutil/attributes.h" #include "libavutil/mem.h" #include "avcodec.h" #define BITSTREAM_READER_LE #include "get_bits.h" #include "internal.h" typedef struct Escape130Context { uint8_t *old_y_avg; uint8_t *new_y, *old_y; uint8_t *new_u, *old_u; uint8_t *new_v, *old_v; uint8_t *buf1, *buf2; int linesize[3]; } Escape130Context; static const uint8_t offset_table[] = { 2, 4, 10, 20 }; static const int8_t sign_table[64][4] = { { 0, 0, 0, 0 }, { -1, 1, 0, 0 }, { 1, -1, 0, 0 }, { -1, 0, 1, 0 }, { -1, 1, 1, 0 }, { 0, -1, 1, 0 }, { 1, -1, 1, 0 }, { -1, -1, 1, 0 }, { 1, 0, -1, 0 }, { 0, 1, -1, 0 }, { 1, 1, -1, 0 }, { -1, 1, -1, 0 }, { 1, -1, -1, 0 }, { -1, 0, 0, 1 }, { -1, 1, 0, 1 }, { 0, -1, 0, 1 }, { 0, 0, 0, 0 }, { 1, -1, 0, 1 }, { -1, -1, 0, 1 }, { -1, 0, 1, 1 }, { -1, 1, 1, 1 }, { 0, -1, 1, 1 }, { 1, -1, 1, 1 }, { -1, -1, 1, 1 }, { 0, 0, -1, 1 }, { 1, 0, -1, 1 }, { -1, 0, -1, 1 }, { 0, 1, -1, 1 }, { 1, 1, -1, 1 }, { -1, 1, -1, 1 }, { 0, -1, -1, 1 }, { 1, -1, -1, 1 }, { 0, 0, 0, 0 }, { -1, -1, -1, 1 }, { 1, 0, 0, -1 }, { 0, 1, 0, -1 }, { 1, 1, 0, -1 }, { -1, 1, 0, -1 }, { 1, -1, 0, -1 }, { 0, 0, 1, -1 }, { 1, 0, 1, -1 }, { -1, 0, 1, -1 }, { 0, 1, 1, -1 }, { 1, 1, 1, -1 }, { -1, 1, 1, -1 }, { 0, -1, 1, -1 }, { 1, -1, 1, -1 }, { -1, -1, 1, -1 }, { 0, 0, 0, 0 }, { 1, 0, -1, -1 }, { 0, 1, -1, -1 }, { 1, 1, -1, -1 }, { -1, 1, -1, -1 }, { 1, -1, -1, -1 } }; static const int8_t luma_adjust[] = { -4, -3, -2, -1, 1, 2, 3, 4 }; static const int8_t chroma_adjust[2][8] = { { 1, 1, 0, -1, -1, -1, 0, 1 }, { 0, 1, 1, 1, 0, -1, -1, -1 } }; static const uint8_t chroma_vals[] = { 20, 28, 36, 44, 52, 60, 68, 76, 84, 92, 100, 106, 112, 116, 120, 124, 128, 132, 136, 140, 144, 150, 156, 164, 172, 180, 188, 196, 204, 212, 220, 228 }; static av_cold int escape130_decode_init(AVCodecContext *avctx) { Escape130Context *s = avctx->priv_data; avctx->pix_fmt = AV_PIX_FMT_YUV420P; if ((avctx->width & 1) || (avctx->height & 1)) { av_log(avctx, AV_LOG_ERROR, "Dimensions should be a multiple of two.\n"); return AVERROR_INVALIDDATA; } s->old_y_avg = av_malloc(avctx->width * avctx->height / 4); s->buf1 = av_malloc(avctx->width * avctx->height * 3 / 2); s->buf2 = av_malloc(avctx->width * avctx->height * 3 / 2); if (!s->old_y_avg || !s->buf1 || !s->buf2) { av_freep(&s->old_y_avg); av_freep(&s->buf1); av_freep(&s->buf2); av_log(avctx, AV_LOG_ERROR, "Could not allocate buffer.\n"); return AVERROR(ENOMEM); } s->linesize[0] = avctx->width; s->linesize[1] = s->linesize[2] = avctx->width / 2; s->new_y = s->buf1; s->new_u = s->new_y + avctx->width * avctx->height; s->new_v = s->new_u + avctx->width * avctx->height / 4; s->old_y = s->buf2; s->old_u = s->old_y + avctx->width * avctx->height; s->old_v = s->old_u + avctx->width * avctx->height / 4; memset(s->old_y, 0, avctx->width * avctx->height); memset(s->old_u, 0x10, avctx->width * avctx->height / 4); memset(s->old_v, 0x10, avctx->width * avctx->height / 4); return 0; } static av_cold int escape130_decode_close(AVCodecContext *avctx) { Escape130Context *s = avctx->priv_data; av_freep(&s->old_y_avg); av_freep(&s->buf1); av_freep(&s->buf2); return 0; } static int decode_skip_count(GetBitContext* gb) { int value; if (get_bits_left(gb) < 1+3) return -1; value = get_bits1(gb); if (value) return 0; value = get_bits(gb, 3); if (value) return value; value = get_bits(gb, 8); if (value) return value + 7; value = get_bits(gb, 15); if (value) return value + 262; return -1; } static int escape130_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) { int buf_size = avpkt->size; Escape130Context *s = avctx->priv_data; AVFrame *pic = data; GetBitContext gb; int ret; uint8_t *old_y, *old_cb, *old_cr, *new_y, *new_cb, *new_cr; uint8_t *dstY, *dstU, *dstV; unsigned old_y_stride, old_cb_stride, old_cr_stride, new_y_stride, new_cb_stride, new_cr_stride; unsigned total_blocks = avctx->width * avctx->height / 4, block_index, block_x = 0; unsigned y[4] = { 0 }, cb = 0x10, cr = 0x10; int skip = -1, y_avg = 0, i, j; uint8_t *ya = s->old_y_avg; // first 16 bytes are header; no useful information in here if (buf_size <= 16) { av_log(avctx, AV_LOG_ERROR, "Insufficient frame data\n"); return AVERROR_INVALIDDATA; } if ((ret = ff_get_buffer(avctx, pic, 0)) < 0) return ret; if ((ret = init_get_bits8(&gb, avpkt->data, avpkt->size)) < 0) return ret; skip_bits_long(&gb, 16 * 8); new_y = s->new_y; new_cb = s->new_u; new_cr = s->new_v; new_y_stride = s->linesize[0]; new_cb_stride = s->linesize[1]; new_cr_stride = s->linesize[2]; old_y = s->old_y; old_cb = s->old_u; old_cr = s->old_v; old_y_stride = s->linesize[0]; old_cb_stride = s->linesize[1]; old_cr_stride = s->linesize[2]; for (block_index = 0; block_index < total_blocks; block_index++) { // Note that this call will make us skip the rest of the blocks // if the frame ends prematurely. if (skip == -1) skip = decode_skip_count(&gb); if (skip == -1) { av_log(avctx, AV_LOG_ERROR, "Error decoding skip value\n"); return AVERROR_INVALIDDATA; } if (skip) { y[0] = old_y[0]; y[1] = old_y[1]; y[2] = old_y[old_y_stride]; y[3] = old_y[old_y_stride + 1]; y_avg = ya[0]; cb = old_cb[0]; cr = old_cr[0]; } else { if (get_bits1(&gb)) { unsigned sign_selector = get_bits(&gb, 6); unsigned difference_selector = get_bits(&gb, 2); y_avg = 2 * get_bits(&gb, 5); for (i = 0; i < 4; i++) { y[i] = av_clip(y_avg + offset_table[difference_selector] * sign_table[sign_selector][i], 0, 63); } } else if (get_bits1(&gb)) { if (get_bits1(&gb)) { y_avg = get_bits(&gb, 6); } else { unsigned adjust_index = get_bits(&gb, 3); y_avg = (y_avg + luma_adjust[adjust_index]) & 63; } for (i = 0; i < 4; i++) y[i] = y_avg; } if (get_bits1(&gb)) { if (get_bits1(&gb)) { cb = get_bits(&gb, 5); cr = get_bits(&gb, 5); } else { unsigned adjust_index = get_bits(&gb, 3); cb = (cb + chroma_adjust[0][adjust_index]) & 31; cr = (cr + chroma_adjust[1][adjust_index]) & 31; } } } *ya++ = y_avg; new_y[0] = y[0]; new_y[1] = y[1]; new_y[new_y_stride] = y[2]; new_y[new_y_stride + 1] = y[3]; *new_cb = cb; *new_cr = cr; old_y += 2; old_cb++; old_cr++; new_y += 2; new_cb++; new_cr++; block_x++; if (block_x * 2 == avctx->width) { block_x = 0; old_y += old_y_stride * 2 - avctx->width; old_cb += old_cb_stride - avctx->width / 2; old_cr += old_cr_stride - avctx->width / 2; new_y += new_y_stride * 2 - avctx->width; new_cb += new_cb_stride - avctx->width / 2; new_cr += new_cr_stride - avctx->width / 2; } skip--; } new_y = s->new_y; new_cb = s->new_u; new_cr = s->new_v; dstY = pic->data[0]; dstU = pic->data[1]; dstV = pic->data[2]; for (j = 0; j < avctx->height; j++) { for (i = 0; i < avctx->width; i++) dstY[i] = new_y[i] << 2; dstY += pic->linesize[0]; new_y += new_y_stride; } for (j = 0; j < avctx->height / 2; j++) { for (i = 0; i < avctx->width / 2; i++) { dstU[i] = chroma_vals[new_cb[i]]; dstV[i] = chroma_vals[new_cr[i]]; } dstU += pic->linesize[1]; dstV += pic->linesize[2]; new_cb += new_cb_stride; new_cr += new_cr_stride; } av_dlog(avctx, "Frame data: provided %d bytes, used %d bytes\n", buf_size, get_bits_count(&gb) >> 3); FFSWAP(uint8_t*, s->old_y, s->new_y); FFSWAP(uint8_t*, s->old_u, s->new_u); FFSWAP(uint8_t*, s->old_v, s->new_v); *got_frame = 1; return buf_size; } AVCodec ff_escape130_decoder = { .name = "escape130", .long_name = NULL_IF_CONFIG_SMALL("Escape 130"), .type = AVMEDIA_TYPE_VIDEO, .id = AV_CODEC_ID_ESCAPE130, .priv_data_size = sizeof(Escape130Context), .init = escape130_decode_init, .close = escape130_decode_close, .decode = escape130_decode_frame, .capabilities = CODEC_CAP_DR1, };