| /* |
| * SGI RLE 8-bit decoder |
| * Copyright (c) 2012 Peter Ross |
| * |
| * 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 |
| * SGI RLE 8-bit decoder |
| */ |
| |
| #include "libavutil/intreadwrite.h" |
| #include "avcodec.h" |
| #include "bytestream.h" |
| |
| static av_cold int sgirle_decode_init(AVCodecContext *avctx) |
| { |
| avctx->pix_fmt = AV_PIX_FMT_BGR8; |
| avctx->coded_frame = avcodec_alloc_frame(); |
| if (!avctx->coded_frame) |
| return AVERROR(ENOMEM); |
| return 0; |
| } |
| |
| /** |
| * Convert SGI RGB332 pixel into PIX_FMT_BGR8 |
| * SGI RGB332 is packed RGB 3:3:2, 8bpp, (msb)3R 2B 3G(lsb) |
| */ |
| #define RGB332_TO_BGR8(x) (((x << 3) & 0xC0) | ((x << 3) & 0x38) | ((x >> 5) & 7)) |
| |
| static av_always_inline void memcpy_rgb332_to_bgr8(uint8_t *dst, const uint8_t *src, int size) |
| { |
| int i; |
| for (i = 0; i < size; i++) |
| dst[i] = RGB332_TO_BGR8(src[i]); |
| } |
| |
| /** |
| * @param[out] dst Destination buffer |
| * @param[in] src Source buffer |
| * @param src_size Source buffer size (bytes) |
| * @param width Width of destination buffer (pixels) |
| * @param height Height of destination buffer (pixels) |
| * @param linesize Line size of destination buffer (bytes) |
| * @return <0 on error |
| */ |
| static int decode_sgirle8(AVCodecContext *avctx, uint8_t *dst, const uint8_t *src, int src_size, int width, int height, int linesize) |
| { |
| const uint8_t *src_end = src + src_size; |
| int x = 0, y = 0; |
| |
| #define INC_XY(n) \ |
| x += n; \ |
| if (x >= width) { \ |
| y++; \ |
| if (y >= height) \ |
| return 0; \ |
| x = 0; \ |
| } |
| |
| while (src_end - src >= 2) { |
| uint8_t v = *src++; |
| if (v > 0 && v < 0xC0) { |
| do { |
| int length = FFMIN(v, width - x); |
| memset(dst + y*linesize + x, RGB332_TO_BGR8(*src), length); |
| INC_XY(length); |
| v -= length; |
| } while (v > 0); |
| src++; |
| } else if (v >= 0xC1) { |
| v -= 0xC0; |
| do { |
| int length = FFMIN3(v, width - x, src_end - src); |
| if (src_end - src < length) |
| break; |
| memcpy_rgb332_to_bgr8(dst + y*linesize + x, src, length); |
| INC_XY(length); |
| src += length; |
| v -= length; |
| } while (v > 0); |
| } else { |
| av_log_ask_for_sample(avctx, "unknown opcode\n"); |
| return AVERROR_PATCHWELCOME; |
| } |
| } |
| return 0; |
| } |
| |
| static int sgirle_decode_frame(AVCodecContext *avctx, |
| void *data, int *got_frame, |
| AVPacket *avpkt) |
| { |
| AVFrame *frame = avctx->coded_frame; |
| int ret; |
| |
| frame->reference = 3; |
| frame->buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | |
| FF_BUFFER_HINTS_REUSABLE | FF_BUFFER_HINTS_READABLE; |
| ret = avctx->reget_buffer(avctx, frame); |
| if (ret < 0) { |
| av_log (avctx, AV_LOG_ERROR, "reget_buffer() failed\n"); |
| return ret; |
| } |
| |
| ret = decode_sgirle8(avctx, frame->data[0], avpkt->data, avpkt->size, avctx->width, avctx->height, frame->linesize[0]); |
| if (ret < 0) |
| return ret; |
| |
| *got_frame = 1; |
| *(AVFrame*)data = *frame; |
| |
| return avpkt->size; |
| } |
| |
| static av_cold int sgirle_decode_end(AVCodecContext *avctx) |
| { |
| if (avctx->coded_frame->data[0]) |
| avctx->release_buffer(avctx, avctx->coded_frame); |
| av_freep(&avctx->coded_frame); |
| return 0; |
| } |
| |
| AVCodec ff_sgirle_decoder = { |
| .name = "sgirle", |
| .type = AVMEDIA_TYPE_VIDEO, |
| .id = AV_CODEC_ID_SGIRLE, |
| .init = sgirle_decode_init, |
| .close = sgirle_decode_end, |
| .decode = sgirle_decode_frame, |
| .capabilities = CODEC_CAP_DR1, |
| .long_name = NULL_IF_CONFIG_SMALL("SGI RLE 8-bit"), |
| }; |