FFmpeg
8bps.c
Go to the documentation of this file.
1 /*
2  * Quicktime Planar RGB (8BPS) Video Decoder
3  * Copyright (C) 2003 Roberto Togni
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 /**
23  * @file
24  * QT 8BPS Video Decoder by Roberto Togni
25  * For more information about the 8BPS format, visit:
26  * http://www.pcisys.net/~melanson/codecs/
27  *
28  * Supports: PAL8 (RGB 8bpp, paletted)
29  * : BGR24 (RGB 24bpp) (can also output it as RGB32)
30  * : RGB32 (RGB 32bpp, 4th plane is alpha)
31  */
32 
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 
37 #include "libavutil/internal.h"
38 #include "libavutil/intreadwrite.h"
39 #include "avcodec.h"
40 #include "decode.h"
41 #include "internal.h"
42 
43 
44 static const enum AVPixelFormat pixfmt_rgb24[] = {
46 
47 typedef struct EightBpsContext {
49 
50  unsigned char planes;
51  unsigned char planemap[4];
52 
53  uint32_t pal[256];
55 
56 static int decode_frame(AVCodecContext *avctx, void *data,
57  int *got_frame, AVPacket *avpkt)
58 {
59  AVFrame *frame = data;
60  const uint8_t *buf = avpkt->data;
61  int buf_size = avpkt->size;
62  EightBpsContext * const c = avctx->priv_data;
63  const unsigned char *encoded = buf;
64  unsigned char *pixptr, *pixptr_end;
65  unsigned int height = avctx->height; // Real image height
66  unsigned int dlen, p, row;
67  const unsigned char *lp, *dp, *ep;
68  unsigned char count;
69  unsigned int px_inc;
70  unsigned int planes = c->planes;
71  unsigned char *planemap = c->planemap;
72  int ret;
73 
74  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
75  return ret;
76 
77  ep = encoded + buf_size;
78 
79  /* Set data pointer after line lengths */
80  dp = encoded + planes * (height << 1);
81 
82  px_inc = planes + (avctx->pix_fmt == AV_PIX_FMT_0RGB32);
83 
84  for (p = 0; p < planes; p++) {
85  /* Lines length pointer for this plane */
86  lp = encoded + p * (height << 1);
87 
88  /* Decode a plane */
89  for (row = 0; row < height; row++) {
90  pixptr = frame->data[0] + row * frame->linesize[0] + planemap[p];
91  pixptr_end = pixptr + frame->linesize[0];
92  if (ep - lp < row * 2 + 2)
93  return AVERROR_INVALIDDATA;
94  dlen = av_be2ne16(*(const unsigned short *)(lp + row * 2));
95  /* Decode a row of this plane */
96  while (dlen > 0) {
97  if (ep - dp <= 1)
98  return AVERROR_INVALIDDATA;
99  if ((count = *dp++) <= 127) {
100  count++;
101  dlen -= count + 1;
102  if (pixptr_end - pixptr < count * px_inc)
103  break;
104  if (ep - dp < count)
105  return AVERROR_INVALIDDATA;
106  while (count--) {
107  *pixptr = *dp++;
108  pixptr += px_inc;
109  }
110  } else {
111  count = 257 - count;
112  if (pixptr_end - pixptr < count * px_inc)
113  break;
114  while (count--) {
115  *pixptr = *dp;
116  pixptr += px_inc;
117  }
118  dp++;
119  dlen -= 2;
120  }
121  }
122  }
123  }
124 
125  if (avctx->bits_per_coded_sample <= 8) {
126  frame->palette_has_changed = ff_copy_palette(c->pal, avpkt, avctx);
127 
128  memcpy (frame->data[1], c->pal, AVPALETTE_SIZE);
129  }
130 
131  *got_frame = 1;
132 
133  /* always report that the buffer was completely consumed */
134  return buf_size;
135 }
136 
138 {
139  EightBpsContext * const c = avctx->priv_data;
140 
141  c->avctx = avctx;
142 
143  switch (avctx->bits_per_coded_sample) {
144  case 8:
145  avctx->pix_fmt = AV_PIX_FMT_PAL8;
146  c->planes = 1;
147  c->planemap[0] = 0; // 1st plane is palette indexes
148  break;
149  case 24:
150  avctx->pix_fmt = ff_get_format(avctx, pixfmt_rgb24);
151  c->planes = 3;
152  c->planemap[0] = 2; // 1st plane is red
153  c->planemap[1] = 1; // 2nd plane is green
154  c->planemap[2] = 0; // 3rd plane is blue
155  break;
156  case 32:
157  avctx->pix_fmt = AV_PIX_FMT_RGB32;
158  c->planes = 4;
159  /* handle planemap setup later for decoding rgb24 data as rbg32 */
160  break;
161  default:
162  av_log(avctx, AV_LOG_ERROR, "Error: Unsupported color depth: %u.\n",
163  avctx->bits_per_coded_sample);
164  return AVERROR_INVALIDDATA;
165  }
166 
167  if (avctx->pix_fmt == AV_PIX_FMT_RGB32) {
168  c->planemap[0] = HAVE_BIGENDIAN ? 1 : 2; // 1st plane is red
169  c->planemap[1] = HAVE_BIGENDIAN ? 2 : 1; // 2nd plane is green
170  c->planemap[2] = HAVE_BIGENDIAN ? 3 : 0; // 3rd plane is blue
171  c->planemap[3] = HAVE_BIGENDIAN ? 0 : 3; // 4th plane is alpha
172  }
173  return 0;
174 }
175 
177  .name = "8bps",
178  .long_name = NULL_IF_CONFIG_SMALL("QuickTime 8BPS video"),
179  .type = AVMEDIA_TYPE_VIDEO,
180  .id = AV_CODEC_ID_8BPS,
181  .priv_data_size = sizeof(EightBpsContext),
182  .init = decode_init,
183  .decode = decode_frame,
184  .capabilities = AV_CODEC_CAP_DR1,
185 };
EightBpsContext::planemap
unsigned char planemap[4]
Definition: 8bps.c:51
AVCodec
AVCodec.
Definition: codec.h:197
AVPixelFormat
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
pixfmt_rgb24
static enum AVPixelFormat pixfmt_rgb24[]
Definition: 8bps.c:44
init
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
ff_get_format
int ff_get_format(AVCodecContext *avctx, const enum AVPixelFormat *fmt)
Select the (possibly hardware accelerated) pixel format.
Definition: decode.c:1072
decode_init
static av_cold int decode_init(AVCodecContext *avctx)
Definition: 8bps.c:137
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:303
internal.h
AVPacket::data
uint8_t * data
Definition: packet.h:365
data
const char data[16]
Definition: mxf.c:142
AV_PIX_FMT_BGR24
@ AV_PIX_FMT_BGR24
packed RGB 8:8:8, 24bpp, BGRBGR...
Definition: pixfmt.h:69
EightBpsContext::pal
uint32_t pal[256]
Definition: 8bps.c:53
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:181
av_cold
#define av_cold
Definition: attributes.h:90
ff_eightbps_decoder
const AVCodec ff_eightbps_decoder
Definition: 8bps.c:176
decode
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
intreadwrite.h
decode.h
EightBpsContext::avctx
AVCodecContext * avctx
Definition: 8bps.c:48
AVPALETTE_SIZE
#define AVPALETTE_SIZE
Definition: pixfmt.h:32
EightBpsContext::planes
unsigned char planes
Definition: 8bps.c:50
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1638
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
AVPacket::size
int size
Definition: packet.h:366
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
AV_CODEC_ID_8BPS
@ AV_CODEC_ID_8BPS
Definition: codec_id.h:97
height
#define height
AV_PIX_FMT_RGB32
#define AV_PIX_FMT_RGB32
Definition: pixfmt.h:362
AVCodecContext::bits_per_coded_sample
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
Definition: avcodec.h:1524
EightBpsContext
Definition: 8bps.c:47
internal.h
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:204
AVCodecContext::height
int height
Definition: avcodec.h:674
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:711
avcodec.h
AV_PIX_FMT_PAL8
@ AV_PIX_FMT_PAL8
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:77
ret
ret
Definition: filter_design.txt:187
frame
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Definition: filter_design.txt:264
AV_PIX_FMT_0RGB32
#define AV_PIX_FMT_0RGB32
Definition: pixfmt.h:366
AVCodecContext
main external API structure.
Definition: avcodec.h:501
AV_PIX_FMT_NONE
@ AV_PIX_FMT_NONE
Definition: pixfmt.h:65
decode_frame
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: 8bps.c:56
av_be2ne16
#define av_be2ne16(x)
Definition: bswap.h:92
planes
static const struct @322 planes[]
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:528
AVPacket
This structure stores compressed data.
Definition: packet.h:342
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
ff_copy_palette
int ff_copy_palette(void *dst, const AVPacket *src, void *logctx)
Check whether the side-data of src contains a palette of size AVPALETTE_SIZE; if so,...
Definition: decode.c:1840