forked from KolibriOS/kolibrios
301 lines
9.0 KiB
C
301 lines
9.0 KiB
C
/*
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* SGI image decoder
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* Todd Kirby <doubleshot@pacbell.net>
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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/imgutils.h"
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#include "libavutil/avassert.h"
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#include "avcodec.h"
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#include "bytestream.h"
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#include "internal.h"
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#include "sgi.h"
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typedef struct SgiState {
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AVCodecContext *avctx;
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unsigned int width;
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unsigned int height;
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unsigned int depth;
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unsigned int bytes_per_channel;
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int linesize;
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GetByteContext g;
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} SgiState;
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/**
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* Expand an RLE row into a channel.
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* @param s the current image state
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* @param out_buf Points to one line after the output buffer.
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* @param len length of out_buf in bytes
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* @param pixelstride pixel stride of input buffer
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* @return size of output in bytes, else return error code.
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*/
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static int expand_rle_row8(SgiState *s, uint8_t *out_buf,
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int len, int pixelstride)
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{
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unsigned char pixel, count;
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unsigned char *orig = out_buf;
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uint8_t *out_end = out_buf + len;
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while (out_buf < out_end) {
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if (bytestream2_get_bytes_left(&s->g) < 1)
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return AVERROR_INVALIDDATA;
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pixel = bytestream2_get_byteu(&s->g);
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if (!(count = (pixel & 0x7f))) {
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break;
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}
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/* Check for buffer overflow. */
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if (out_end - out_buf <= pixelstride * (count - 1)) {
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av_log(s->avctx, AV_LOG_ERROR, "Invalid pixel count.\n");
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return AVERROR_INVALIDDATA;
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}
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if (pixel & 0x80) {
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while (count--) {
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*out_buf = bytestream2_get_byte(&s->g);
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out_buf += pixelstride;
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}
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} else {
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pixel = bytestream2_get_byte(&s->g);
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while (count--) {
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*out_buf = pixel;
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out_buf += pixelstride;
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}
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}
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}
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return (out_buf - orig) / pixelstride;
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}
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static int expand_rle_row16(SgiState *s, uint16_t *out_buf,
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int len, int pixelstride)
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{
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unsigned short pixel;
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unsigned char count;
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unsigned short *orig = out_buf;
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uint16_t *out_end = out_buf + len;
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while (out_buf < out_end) {
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if (bytestream2_get_bytes_left(&s->g) < 2)
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return AVERROR_INVALIDDATA;
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pixel = bytestream2_get_be16u(&s->g);
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if (!(count = (pixel & 0x7f)))
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break;
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/* Check for buffer overflow. */
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if (out_end - out_buf <= pixelstride * (count - 1)) {
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av_log(s->avctx, AV_LOG_ERROR, "Invalid pixel count.\n");
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return AVERROR_INVALIDDATA;
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}
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if (pixel & 0x80) {
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while (count--) {
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pixel = bytestream2_get_ne16(&s->g);
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AV_WN16A(out_buf, pixel);
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out_buf += pixelstride;
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}
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} else {
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pixel = bytestream2_get_ne16(&s->g);
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while (count--) {
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AV_WN16A(out_buf, pixel);
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out_buf += pixelstride;
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}
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}
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}
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return (out_buf - orig) / pixelstride;
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}
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/**
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* Read a run length encoded SGI image.
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* @param out_buf output buffer
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* @param s the current image state
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* @return 0 if no error, else return error code.
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*/
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static int read_rle_sgi(uint8_t *out_buf, SgiState *s)
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{
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uint8_t *dest_row;
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unsigned int len = s->height * s->depth * 4;
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GetByteContext g_table = s->g;
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unsigned int y, z;
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unsigned int start_offset;
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int linesize, ret;
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/* size of RLE offset and length tables */
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if (len * 2 > bytestream2_get_bytes_left(&s->g)) {
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return AVERROR_INVALIDDATA;
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}
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for (z = 0; z < s->depth; z++) {
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dest_row = out_buf;
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for (y = 0; y < s->height; y++) {
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linesize = s->width * s->depth;
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dest_row -= s->linesize;
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start_offset = bytestream2_get_be32(&g_table);
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bytestream2_seek(&s->g, start_offset, SEEK_SET);
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if (s->bytes_per_channel == 1)
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ret = expand_rle_row8(s, dest_row + z, linesize, s->depth);
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else
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ret = expand_rle_row16(s, (uint16_t *)dest_row + z, linesize, s->depth);
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if (ret != s->width)
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return AVERROR_INVALIDDATA;
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}
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}
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return 0;
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}
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/**
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* Read an uncompressed SGI image.
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* @param out_buf output buffer
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* @param s the current image state
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* @return 0 if read success, else return error code.
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*/
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static int read_uncompressed_sgi(unsigned char *out_buf, SgiState *s)
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{
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int x, y, z;
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unsigned int offset = s->height * s->width * s->bytes_per_channel;
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GetByteContext gp[4];
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uint8_t *out_end;
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/* Test buffer size. */
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if (offset * s->depth > bytestream2_get_bytes_left(&s->g))
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return AVERROR_INVALIDDATA;
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/* Create a reader for each plane */
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for (z = 0; z < s->depth; z++) {
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gp[z] = s->g;
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bytestream2_skip(&gp[z], z * offset);
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}
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for (y = s->height - 1; y >= 0; y--) {
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out_end = out_buf + (y * s->linesize);
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if (s->bytes_per_channel == 1) {
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for (x = s->width; x > 0; x--)
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for (z = 0; z < s->depth; z++)
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*out_end++ = bytestream2_get_byteu(&gp[z]);
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} else {
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uint16_t *out16 = (uint16_t *)out_end;
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for (x = s->width; x > 0; x--)
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for (z = 0; z < s->depth; z++)
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*out16++ = bytestream2_get_ne16u(&gp[z]);
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}
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}
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return 0;
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}
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static int decode_frame(AVCodecContext *avctx,
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void *data, int *got_frame,
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AVPacket *avpkt)
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{
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SgiState *s = avctx->priv_data;
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AVFrame *p = data;
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unsigned int dimension, rle;
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int ret = 0;
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uint8_t *out_buf, *out_end;
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bytestream2_init(&s->g, avpkt->data, avpkt->size);
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if (bytestream2_get_bytes_left(&s->g) < SGI_HEADER_SIZE) {
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av_log(avctx, AV_LOG_ERROR, "buf_size too small (%d)\n", avpkt->size);
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return AVERROR_INVALIDDATA;
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}
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/* Test for SGI magic. */
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if (bytestream2_get_be16u(&s->g) != SGI_MAGIC) {
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av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
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return AVERROR_INVALIDDATA;
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}
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rle = bytestream2_get_byteu(&s->g);
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s->bytes_per_channel = bytestream2_get_byteu(&s->g);
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dimension = bytestream2_get_be16u(&s->g);
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s->width = bytestream2_get_be16u(&s->g);
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s->height = bytestream2_get_be16u(&s->g);
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s->depth = bytestream2_get_be16u(&s->g);
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if (s->bytes_per_channel != 1 && s->bytes_per_channel != 2) {
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av_log(avctx, AV_LOG_ERROR, "wrong channel number\n");
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return AVERROR_INVALIDDATA;
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}
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/* Check for supported image dimensions. */
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if (dimension != 2 && dimension != 3) {
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av_log(avctx, AV_LOG_ERROR, "wrong dimension number\n");
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return AVERROR_INVALIDDATA;
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}
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if (s->depth == SGI_GRAYSCALE) {
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avctx->pix_fmt = s->bytes_per_channel == 2 ? AV_PIX_FMT_GRAY16BE : AV_PIX_FMT_GRAY8;
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} else if (s->depth == SGI_RGB) {
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avctx->pix_fmt = s->bytes_per_channel == 2 ? AV_PIX_FMT_RGB48BE : AV_PIX_FMT_RGB24;
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} else if (s->depth == SGI_RGBA) {
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avctx->pix_fmt = s->bytes_per_channel == 2 ? AV_PIX_FMT_RGBA64BE : AV_PIX_FMT_RGBA;
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} else {
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av_log(avctx, AV_LOG_ERROR, "wrong picture format\n");
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return AVERROR_INVALIDDATA;
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}
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ret = ff_set_dimensions(avctx, s->width, s->height);
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if (ret < 0)
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return ret;
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if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
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return ret;
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p->pict_type = AV_PICTURE_TYPE_I;
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p->key_frame = 1;
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out_buf = p->data[0];
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out_end = out_buf + p->linesize[0] * s->height;
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s->linesize = p->linesize[0];
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/* Skip header. */
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bytestream2_seek(&s->g, SGI_HEADER_SIZE, SEEK_SET);
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if (rle) {
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ret = read_rle_sgi(out_end, s);
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} else {
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ret = read_uncompressed_sgi(out_buf, s);
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}
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if (ret)
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return ret;
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*got_frame = 1;
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return avpkt->size;
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}
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static av_cold int sgi_decode_init(AVCodecContext *avctx)
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{
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SgiState *s = avctx->priv_data;
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s->avctx = avctx;
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return 0;
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}
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AVCodec ff_sgi_decoder = {
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.name = "sgi",
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.long_name = NULL_IF_CONFIG_SMALL("SGI image"),
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.type = AVMEDIA_TYPE_VIDEO,
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.id = AV_CODEC_ID_SGI,
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.priv_data_size = sizeof(SgiState),
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.decode = decode_frame,
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.init = sgi_decode_init,
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.capabilities = AV_CODEC_CAP_DR1,
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};
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