| /* |
| * 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" |
| |
| #define BITSTREAM_READER_LE |
| #include "avcodec.h" |
| #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; |
| } |
| |
| ff_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 = AV_CODEC_CAP_DR1, |
| }; |
