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aliaspixdec.c
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1 /*
2  * Alias PIX image decoder
3  * Copyright (C) 2014 Vittorio Giovara <vittorio.giovara@gmail.com>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "libavutil/intreadwrite.h"
23 
24 #include "avcodec.h"
25 #include "bytestream.h"
26 #include "internal.h"
27 
28 #define ALIAS_HEADER_SIZE 10
29 
30 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
31  AVPacket *avpkt)
32 {
33  AVFrame *f = data;
34  GetByteContext gb;
35  int width, height, ret, bits_pixel, pixel;
36  uint8_t *out_buf;
37  uint8_t count;
38  int x, y;
39 
40  bytestream2_init(&gb, avpkt->data, avpkt->size);
41 
43  av_log(avctx, AV_LOG_ERROR, "Header too small %d.\n", avpkt->size);
44  return AVERROR_INVALIDDATA;
45  }
46 
47  width = bytestream2_get_be16u(&gb);
48  height = bytestream2_get_be16u(&gb);
49  bytestream2_skipu(&gb, 4); // obsolete X, Y offset
50  bits_pixel = bytestream2_get_be16u(&gb);
51 
52  if (bits_pixel == 24)
53  avctx->pix_fmt = AV_PIX_FMT_BGR24;
54  else if (bits_pixel == 8)
55  avctx->pix_fmt = AV_PIX_FMT_GRAY8;
56  else {
57  av_log(avctx, AV_LOG_ERROR, "Invalid pixel format.\n");
58  return AVERROR_INVALIDDATA;
59  }
60 
61  ret = ff_set_dimensions(avctx, width, height);
62  if (ret < 0)
63  return ret;
64 
65  ret = ff_get_buffer(avctx, f, 0);
66  if (ret < 0)
67  return ret;
68 
70  f->key_frame = 1;
71 
72  x = 0;
73  y = 1;
74  out_buf = f->data[0];
75  while (bytestream2_get_bytes_left(&gb) > 0) {
76  int i;
77 
78  /* set buffer at the right position at every new line */
79  if (x == avctx->width) {
80  x = 0;
81  out_buf = f->data[0] + f->linesize[0] * y++;
82  if (y > avctx->height) {
83  av_log(avctx, AV_LOG_ERROR,
84  "Ended frame decoding with %d bytes left.\n",
86  return AVERROR_INVALIDDATA;
87  }
88  }
89 
90  /* read packet and copy data */
91  count = bytestream2_get_byteu(&gb);
92  if (!count || x + count > avctx->width) {
93  av_log(avctx, AV_LOG_ERROR, "Invalid run length %d.\n", count);
94  return AVERROR_INVALIDDATA;
95  }
96 
97  if (avctx->pix_fmt == AV_PIX_FMT_BGR24) {
98  pixel = bytestream2_get_be24(&gb);
99  for (i = 0; i < count; i++) {
100  AV_WB24(out_buf, pixel);
101  out_buf += 3;
102  }
103  } else { // AV_PIX_FMT_GRAY8
104  pixel = bytestream2_get_byte(&gb);
105  for (i = 0; i < count; i++)
106  *out_buf++ = pixel;
107  }
108 
109  x += i;
110  }
111 
112  if (x != width || y != height) {
113  av_log(avctx, AV_LOG_ERROR, "Picture stopped at %d,%d.\n", x, y);
114  return AVERROR_INVALIDDATA;
115  }
116 
117  *got_frame = 1;
118  return avpkt->size;
119 }
120 
122  .name = "alias_pix",
123  .long_name = NULL_IF_CONFIG_SMALL("Alias/Wavefront PIX image"),
124  .type = AVMEDIA_TYPE_VIDEO,
125  .id = AV_CODEC_ID_ALIAS_PIX,
126  .decode = decode_frame,
127  .capabilities = AV_CODEC_CAP_DR1,
128 };
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
This structure describes decoded (raw) audio or video data.
Definition: frame.h:201
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
int ff_set_dimensions(AVCodecContext *s, int width, int height)
Check that the provided frame dimensions are valid and set them on the codec context.
Definition: utils.c:196
int size
Definition: avcodec.h:1415
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1711
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:133
AVCodec.
Definition: avcodec.h:3365
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: aliaspixdec.c:30
uint8_t
#define height
uint8_t * data
Definition: avcodec.h:1414
static av_always_inline void bytestream2_skipu(GetByteContext *g, unsigned int size)
Definition: bytestream.h:170
AVCodec ff_alias_pix_decoder
Definition: aliaspixdec.c:121
#define av_log(a,...)
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
#define ALIAS_HEADER_SIZE
Definition: aliaspixdec.c:28
static av_always_inline unsigned int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:154
uint16_t width
Definition: gdv.c:47
const char * name
Name of the codec implementation.
Definition: avcodec.h:3372
GLsizei count
Definition: opengl_enc.c:109
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:284
int width
picture width / height.
Definition: avcodec.h:1674
#define AV_WB24(p, d)
Definition: intreadwrite.h:450
packed RGB 8:8:8, 24bpp, BGRBGR...
Definition: pixfmt.h:65
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:232
main external API structure.
Definition: avcodec.h:1502
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1886
uint8_t pixel
Definition: tiny_ssim.c:42
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:215
Y , 8bpp.
Definition: pixfmt.h:70
common internal api header.
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:279
This structure stores compressed data.
Definition: avcodec.h:1391
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:956