From e50f5d3cf9ef9a16982a5cb4d8b1916cd963aa5b Mon Sep 17 00:00:00 2001 From: Vittorio Giovara Date: Thu, 20 Mar 2014 01:15:25 +0100 Subject: Alias PIX image encoder and decoder --- libavcodec/aliaspixdec.c | 128 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 128 insertions(+) create mode 100644 libavcodec/aliaspixdec.c (limited to 'libavcodec/aliaspixdec.c') diff --git a/libavcodec/aliaspixdec.c b/libavcodec/aliaspixdec.c new file mode 100644 index 0000000000..8969e1765e --- /dev/null +++ b/libavcodec/aliaspixdec.c @@ -0,0 +1,128 @@ +/* + * Alias PIX image decoder + * Copyright (C) 2014 Vittorio Giovara + * + * This file is part of Libav. + * + * Libav 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. + * + * Libav 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 Libav; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "libavutil/intreadwrite.h" + +#include "avcodec.h" +#include "bytestream.h" +#include "internal.h" + +#define ALIAS_HEADER_SIZE 10 + +static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, + AVPacket *avpkt) +{ + AVFrame *f = data; + GetByteContext gb; + int width, height, ret, bits_pixel, pixel; + uint8_t *out_buf; + uint8_t count; + int x, y; + + bytestream2_init(&gb, avpkt->data, avpkt->size); + + if (bytestream2_get_bytes_left(&gb) < ALIAS_HEADER_SIZE) { + av_log(avctx, AV_LOG_ERROR, "Header too small %d.\n", avpkt->size); + return AVERROR_INVALIDDATA; + } + + width = bytestream2_get_be16u(&gb); + height = bytestream2_get_be16u(&gb); + bytestream2_skipu(&gb, 4); // obsolete X, Y offset + bits_pixel = bytestream2_get_be16u(&gb); + + if (bits_pixel == 24) + avctx->pix_fmt = AV_PIX_FMT_BGR24; + else if (bits_pixel == 8) + avctx->pix_fmt = AV_PIX_FMT_GRAY8; + else { + av_log(avctx, AV_LOG_ERROR, "Invalid pixel format.\n"); + return AVERROR_INVALIDDATA; + } + + ret = ff_set_dimensions(avctx, width, height); + if (ret < 0) + return ret; + + ret = ff_get_buffer(avctx, f, 0); + if (ret < 0) + return ret; + + f->pict_type = AV_PICTURE_TYPE_I; + f->key_frame = 1; + + x = 0; + y = 1; + out_buf = f->data[0]; + while (bytestream2_get_bytes_left(&gb) > 0) { + int i; + + /* set buffer at the right position at every new line */ + if (x == avctx->width) { + x = 0; + out_buf = f->data[0] + f->linesize[0] * y++; + if (y > avctx->height) { + av_log(avctx, AV_LOG_ERROR, + "Ended frame decoding with %d bytes left.\n", + bytestream2_get_bytes_left(&gb)); + return AVERROR_INVALIDDATA; + } + } + + /* read packet and copy data */ + count = bytestream2_get_byteu(&gb); + if (!count || x + count > avctx->width) { + av_log(avctx, AV_LOG_ERROR, "Invalid run length %d.\n", count); + return AVERROR_INVALIDDATA; + } + + if (avctx->pix_fmt == AV_PIX_FMT_BGR24) { + pixel = bytestream2_get_be24(&gb); + for (i = 0; i < count; i++) { + AV_WB24(out_buf, pixel); + out_buf += 3; + } + } else { // AV_PIX_FMT_GRAY8 + pixel = bytestream2_get_byte(&gb); + for (i = 0; i < count; i++) + *out_buf++ = pixel; + } + + x += i; + } + + if (x != width || y != height) { + av_log(avctx, AV_LOG_ERROR, "Picture stopped at %d,%d.\n", x, y); + return AVERROR_INVALIDDATA; + } + + *got_frame = 1; + return avpkt->size; +} + +AVCodec ff_alias_pix_decoder = { + .name = "alias_pix", + .long_name = NULL_IF_CONFIG_SMALL("Alias/Wavefront PIX image"), + .type = AVMEDIA_TYPE_VIDEO, + .id = AV_CODEC_ID_ALIAS_PIX, + .decode = decode_frame, + .capabilities = CODEC_CAP_DR1, +}; -- cgit v1.2.3