| /* |
| * SGI image decoder |
| * Todd Kirby <doubleshot@pacbell.net> |
| * |
| * 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/imgutils.h" |
| #include "libavutil/avassert.h" |
| #include "avcodec.h" |
| #include "bytestream.h" |
| #include "sgi.h" |
| |
| typedef struct SgiState { |
| AVFrame picture; |
| unsigned int width; |
| unsigned int height; |
| unsigned int depth; |
| unsigned int bytes_per_channel; |
| int linesize; |
| GetByteContext g; |
| } SgiState; |
| |
| /** |
| * Expand an RLE row into a channel. |
| * @param s the current image state |
| * @param out_buf Points to one line after the output buffer. |
| * @param out_end end of line in output buffer |
| * @param pixelstride pixel stride of input buffer |
| * @return size of output in bytes, -1 if buffer overflows |
| */ |
| static int expand_rle_row(SgiState *s, uint8_t *out_buf, |
| uint8_t *out_end, int pixelstride) |
| { |
| unsigned char pixel, count; |
| unsigned char *orig = out_buf; |
| |
| while (1) { |
| if (bytestream2_get_bytes_left(&s->g) < 1) |
| return AVERROR_INVALIDDATA; |
| pixel = bytestream2_get_byteu(&s->g); |
| if (!(count = (pixel & 0x7f))) { |
| return (out_buf - orig) / pixelstride; |
| } |
| |
| /* Check for buffer overflow. */ |
| if(out_buf + pixelstride * count >= out_end) return -1; |
| |
| if (pixel & 0x80) { |
| while (count--) { |
| *out_buf = bytestream2_get_byte(&s->g); |
| out_buf += pixelstride; |
| } |
| } else { |
| pixel = bytestream2_get_byte(&s->g); |
| |
| while (count--) { |
| *out_buf = pixel; |
| out_buf += pixelstride; |
| } |
| } |
| } |
| } |
| |
| /** |
| * Read a run length encoded SGI image. |
| * @param out_buf output buffer |
| * @param s the current image state |
| * @return 0 if no error, else return error number. |
| */ |
| static int read_rle_sgi(uint8_t *out_buf, SgiState *s) |
| { |
| uint8_t *dest_row; |
| unsigned int len = s->height * s->depth * 4; |
| GetByteContext g_table = s->g; |
| unsigned int y, z; |
| unsigned int start_offset; |
| |
| /* size of RLE offset and length tables */ |
| if (len * 2 > bytestream2_get_bytes_left(&s->g)) { |
| return AVERROR_INVALIDDATA; |
| } |
| |
| for (z = 0; z < s->depth; z++) { |
| dest_row = out_buf; |
| for (y = 0; y < s->height; y++) { |
| dest_row -= s->linesize; |
| start_offset = bytestream2_get_be32(&g_table); |
| bytestream2_seek(&s->g, start_offset, SEEK_SET); |
| if (expand_rle_row(s, dest_row + z, dest_row + FFABS(s->linesize), |
| s->depth) != s->width) { |
| return AVERROR_INVALIDDATA; |
| } |
| } |
| } |
| return 0; |
| } |
| |
| /** |
| * Read an uncompressed SGI image. |
| * @param out_buf output buffer |
| * @param out_end end ofoutput buffer |
| * @param s the current image state |
| * @return 0 if read success, otherwise return -1. |
| */ |
| static int read_uncompressed_sgi(unsigned char* out_buf, uint8_t* out_end, |
| SgiState *s) |
| { |
| int x, y, z; |
| unsigned int offset = s->height * s->width * s->bytes_per_channel; |
| GetByteContext gp[4]; |
| |
| /* Test buffer size. */ |
| if (offset * s->depth > bytestream2_get_bytes_left(&s->g)) |
| return AVERROR_INVALIDDATA; |
| |
| /* Create a reader for each plane */ |
| for (z = 0; z < s->depth; z++) { |
| gp[z] = s->g; |
| bytestream2_skip(&gp[z], z * offset); |
| } |
| |
| for (y = s->height - 1; y >= 0; y--) { |
| out_end = out_buf + (y * s->linesize); |
| if (s->bytes_per_channel == 1) { |
| for (x = s->width; x > 0; x--) |
| for (z = 0; z < s->depth; z++) |
| *out_end++ = bytestream2_get_byteu(&gp[z]); |
| } else { |
| uint16_t *out16 = (uint16_t *)out_end; |
| for (x = s->width; x > 0; x--) |
| for (z = 0; z < s->depth; z++) |
| *out16++ = bytestream2_get_ne16u(&gp[z]); |
| } |
| } |
| return 0; |
| } |
| |
| static int decode_frame(AVCodecContext *avctx, |
| void *data, int *data_size, |
| AVPacket *avpkt) |
| { |
| SgiState *s = avctx->priv_data; |
| AVFrame *picture = data; |
| AVFrame *p = &s->picture; |
| unsigned int dimension, rle; |
| int ret = 0; |
| uint8_t *out_buf, *out_end; |
| |
| bytestream2_init(&s->g, avpkt->data, avpkt->size); |
| if (bytestream2_get_bytes_left(&s->g) < SGI_HEADER_SIZE) { |
| av_log(avctx, AV_LOG_ERROR, "buf_size too small (%d)\n", avpkt->size); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| /* Test for SGI magic. */ |
| if (bytestream2_get_be16(&s->g) != SGI_MAGIC) { |
| av_log(avctx, AV_LOG_ERROR, "bad magic number\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| rle = bytestream2_get_byte(&s->g); |
| s->bytes_per_channel = bytestream2_get_byte(&s->g); |
| dimension = bytestream2_get_be16(&s->g); |
| s->width = bytestream2_get_be16(&s->g); |
| s->height = bytestream2_get_be16(&s->g); |
| s->depth = bytestream2_get_be16(&s->g); |
| |
| if (s->bytes_per_channel != 1 && (s->bytes_per_channel != 2 || rle)) { |
| av_log(avctx, AV_LOG_ERROR, "wrong channel number\n"); |
| return -1; |
| } |
| |
| /* Check for supported image dimensions. */ |
| if (dimension != 2 && dimension != 3) { |
| av_log(avctx, AV_LOG_ERROR, "wrong dimension number\n"); |
| return -1; |
| } |
| |
| if (s->depth == SGI_GRAYSCALE) { |
| avctx->pix_fmt = s->bytes_per_channel == 2 ? PIX_FMT_GRAY16BE : PIX_FMT_GRAY8; |
| } else if (s->depth == SGI_RGB) { |
| avctx->pix_fmt = s->bytes_per_channel == 2 ? PIX_FMT_RGB48BE : PIX_FMT_RGB24; |
| } else if (s->depth == SGI_RGBA) { |
| avctx->pix_fmt = s->bytes_per_channel == 2 ? PIX_FMT_RGBA64BE : PIX_FMT_RGBA; |
| } else { |
| av_log(avctx, AV_LOG_ERROR, "wrong picture format\n"); |
| return -1; |
| } |
| |
| if (av_image_check_size(s->width, s->height, 0, avctx)) |
| return -1; |
| avcodec_set_dimensions(avctx, s->width, s->height); |
| |
| if (p->data[0]) |
| avctx->release_buffer(avctx, p); |
| |
| p->reference = 0; |
| if (avctx->get_buffer(avctx, p) < 0) { |
| av_log(avctx, AV_LOG_ERROR, "get_buffer() failed.\n"); |
| return -1; |
| } |
| |
| p->pict_type = AV_PICTURE_TYPE_I; |
| p->key_frame = 1; |
| out_buf = p->data[0]; |
| |
| out_end = out_buf + p->linesize[0] * s->height; |
| |
| s->linesize = p->linesize[0]; |
| |
| /* Skip header. */ |
| bytestream2_seek(&s->g, SGI_HEADER_SIZE, SEEK_SET); |
| if (rle) { |
| ret = read_rle_sgi(out_end, s); |
| } else { |
| ret = read_uncompressed_sgi(out_buf, out_end, s); |
| } |
| |
| if (ret == 0) { |
| *picture = s->picture; |
| *data_size = sizeof(AVPicture); |
| return avpkt->size; |
| } else { |
| return ret; |
| } |
| } |
| |
| static av_cold int sgi_init(AVCodecContext *avctx){ |
| SgiState *s = avctx->priv_data; |
| |
| avcodec_get_frame_defaults(&s->picture); |
| avctx->coded_frame = &s->picture; |
| |
| return 0; |
| } |
| |
| static av_cold int sgi_end(AVCodecContext *avctx) |
| { |
| SgiState * const s = avctx->priv_data; |
| |
| if (s->picture.data[0]) |
| avctx->release_buffer(avctx, &s->picture); |
| |
| return 0; |
| } |
| |
| AVCodec ff_sgi_decoder = { |
| .name = "sgi", |
| .type = AVMEDIA_TYPE_VIDEO, |
| .id = CODEC_ID_SGI, |
| .priv_data_size = sizeof(SgiState), |
| .init = sgi_init, |
| .close = sgi_end, |
| .decode = decode_frame, |
| .long_name = NULL_IF_CONFIG_SMALL("SGI image"), |
| }; |