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132 lines
3.9 KiB
C
132 lines
3.9 KiB
C
/*
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* Alias PIX image decoder
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* Copyright (C) 2014 Vittorio Giovara <vittorio.giovara@gmail.com>
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "libavutil/intreadwrite.h"
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#include "avcodec.h"
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#include "bytestream.h"
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#include "codec_internal.h"
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#include "decode.h"
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#define ALIAS_HEADER_SIZE 10
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static int decode_frame(AVCodecContext *avctx, AVFrame *f,
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int *got_frame, AVPacket *avpkt)
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{
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GetByteContext gb;
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int width, height, ret, bits_pixel, pixel;
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uint8_t *out_buf;
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uint8_t count;
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int x, y;
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bytestream2_init(&gb, avpkt->data, avpkt->size);
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if (bytestream2_get_bytes_left(&gb) < ALIAS_HEADER_SIZE) {
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av_log(avctx, AV_LOG_ERROR, "Header too small %d.\n", avpkt->size);
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return AVERROR_INVALIDDATA;
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}
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width = bytestream2_get_be16u(&gb);
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height = bytestream2_get_be16u(&gb);
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bytestream2_skipu(&gb, 4); // obsolete X, Y offset
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bits_pixel = bytestream2_get_be16u(&gb);
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if (bits_pixel == 24)
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avctx->pix_fmt = AV_PIX_FMT_BGR24;
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else if (bits_pixel == 8)
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avctx->pix_fmt = AV_PIX_FMT_GRAY8;
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else {
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av_log(avctx, AV_LOG_ERROR, "Invalid pixel format.\n");
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return AVERROR_INVALIDDATA;
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}
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ret = ff_set_dimensions(avctx, width, height);
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if (ret < 0)
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return ret;
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if (bytestream2_get_bytes_left(&gb) < width*height / 255)
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return AVERROR_INVALIDDATA;
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ret = ff_get_buffer(avctx, f, 0);
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if (ret < 0)
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return ret;
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f->pict_type = AV_PICTURE_TYPE_I;
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f->flags |= AV_FRAME_FLAG_KEY;
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x = 0;
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y = 1;
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out_buf = f->data[0];
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while (bytestream2_get_bytes_left(&gb) > 0) {
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int i;
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/* set buffer at the right position at every new line */
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if (x == avctx->width) {
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x = 0;
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out_buf = f->data[0] + f->linesize[0] * y++;
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if (y > avctx->height) {
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av_log(avctx, AV_LOG_ERROR,
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"Ended frame decoding with %d bytes left.\n",
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bytestream2_get_bytes_left(&gb));
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return AVERROR_INVALIDDATA;
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}
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}
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/* read packet and copy data */
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count = bytestream2_get_byteu(&gb);
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if (!count || x + count > avctx->width) {
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av_log(avctx, AV_LOG_ERROR, "Invalid run length %d.\n", count);
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return AVERROR_INVALIDDATA;
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}
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if (avctx->pix_fmt == AV_PIX_FMT_BGR24) {
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pixel = bytestream2_get_be24(&gb);
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for (i = 0; i < count; i++) {
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AV_WB24(out_buf, pixel);
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out_buf += 3;
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}
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} else { // AV_PIX_FMT_GRAY8
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pixel = bytestream2_get_byte(&gb);
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for (i = 0; i < count; i++)
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*out_buf++ = pixel;
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}
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x += i;
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}
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if (x != width || y != height) {
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av_log(avctx, AV_LOG_ERROR, "Picture stopped at %d,%d.\n", x, y);
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return AVERROR_INVALIDDATA;
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}
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*got_frame = 1;
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return avpkt->size;
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}
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const FFCodec ff_alias_pix_decoder = {
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.p.name = "alias_pix",
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CODEC_LONG_NAME("Alias/Wavefront PIX image"),
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.p.type = AVMEDIA_TYPE_VIDEO,
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.p.id = AV_CODEC_ID_ALIAS_PIX,
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.p.capabilities = AV_CODEC_CAP_DR1,
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FF_CODEC_DECODE_CB(decode_frame),
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};
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