/* * 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;     if (bytestream2_get_bytes_left(&gb) < width*height / 255)        return AVERROR_INVALIDDATA;     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 = AV_CODEC_CAP_DR1,};