/* * Alias PIX image decoder * Copyright (C) 2014 Vittorio Giovara <vittorio.giovara@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/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, };