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 <string.h>
34 
35 #include "libavutil/bswap.h"
36 #include "libavutil/internal.h"
37 #include "avcodec.h"
38 #include "codec_internal.h"
39 #include "decode.h"
40 
41 
42 static const enum AVPixelFormat pixfmt_rgb24[] = {
44 
45 typedef struct EightBpsContext {
47 
48  unsigned char planes;
49  unsigned char planemap[4];
51 
53  int *got_frame, AVPacket *avpkt)
54 {
55  const uint8_t *buf = avpkt->data;
56  int buf_size = avpkt->size;
57  EightBpsContext * const c = avctx->priv_data;
58  const unsigned char *encoded = buf;
59  unsigned char *pixptr, *pixptr_end;
60  unsigned int height = avctx->height; // Real image height
61  unsigned int dlen, p, row;
62  const unsigned char *lp, *dp, *ep;
63  unsigned char count;
64  unsigned int px_inc;
65  unsigned int planes = c->planes;
66  unsigned char *planemap = c->planemap;
67  int ret;
68 
69  if (buf_size < planes * height * 2)
70  return AVERROR_INVALIDDATA;
71 
72  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
73  return ret;
74 
75  ep = encoded + buf_size;
76 
77  /* Set data pointer after line lengths */
78  dp = encoded + planes * (height << 1);
79 
80  px_inc = planes + (avctx->pix_fmt == AV_PIX_FMT_0RGB32);
81 
82  for (p = 0; p < planes; p++) {
83  /* Lines length pointer for this plane */
84  lp = encoded + p * (height << 1);
85 
86  /* Decode a plane */
87  for (row = 0; row < height; row++) {
88  pixptr = frame->data[0] + row * frame->linesize[0] + planemap[p];
89  pixptr_end = pixptr + frame->linesize[0];
90  if (ep - lp < row * 2 + 2)
91  return AVERROR_INVALIDDATA;
92  dlen = av_be2ne16(*(const unsigned short *)(lp + row * 2));
93  /* Decode a row of this plane */
94  while (dlen > 0) {
95  if (ep - dp <= 1)
96  return AVERROR_INVALIDDATA;
97  if ((count = *dp++) <= 127) {
98  count++;
99  dlen -= count + 1;
100  if (pixptr_end - pixptr < count * px_inc)
101  break;
102  if (ep - dp < count)
103  return AVERROR_INVALIDDATA;
104  while (count--) {
105  *pixptr = *dp++;
106  pixptr += px_inc;
107  }
108  } else {
109  count = 257 - count;
110  if (pixptr_end - pixptr < count * px_inc)
111  break;
112  while (count--) {
113  *pixptr = *dp;
114  pixptr += px_inc;
115  }
116  dp++;
117  dlen -= 2;
118  }
119  }
120  }
121  }
122 
123  if (avctx->bits_per_coded_sample <= 8) {
124 #if FF_API_PALETTE_HAS_CHANGED
126  frame->palette_has_changed =
127 #endif
128  ff_copy_palette(frame->data[1], avpkt, avctx);
129 #if FF_API_PALETTE_HAS_CHANGED
131 #endif
132  }
133 
134  *got_frame = 1;
135 
136  /* always report that the buffer was completely consumed */
137  return buf_size;
138 }
139 
141 {
142  EightBpsContext * const c = avctx->priv_data;
143 
144  c->avctx = avctx;
145 
146  switch (avctx->bits_per_coded_sample) {
147  case 8:
148  avctx->pix_fmt = AV_PIX_FMT_PAL8;
149  c->planes = 1;
150  c->planemap[0] = 0; // 1st plane is palette indexes
151  break;
152  case 24:
153  avctx->pix_fmt = ff_get_format(avctx, pixfmt_rgb24);
154  c->planes = 3;
155  c->planemap[0] = 2; // 1st plane is red
156  c->planemap[1] = 1; // 2nd plane is green
157  c->planemap[2] = 0; // 3rd plane is blue
158  break;
159  case 32:
160  avctx->pix_fmt = AV_PIX_FMT_RGB32;
161  c->planes = 4;
162  /* handle planemap setup later for decoding rgb24 data as rbg32 */
163  break;
164  default:
165  av_log(avctx, AV_LOG_ERROR, "Error: Unsupported color depth: %u.\n",
166  avctx->bits_per_coded_sample);
167  return AVERROR_INVALIDDATA;
168  }
169 
170  if (avctx->pix_fmt == AV_PIX_FMT_RGB32) {
171  c->planemap[0] = HAVE_BIGENDIAN ? 1 : 2; // 1st plane is red
172  c->planemap[1] = HAVE_BIGENDIAN ? 2 : 1; // 2nd plane is green
173  c->planemap[2] = HAVE_BIGENDIAN ? 3 : 0; // 3rd plane is blue
174  c->planemap[3] = HAVE_BIGENDIAN ? 0 : 3; // 4th plane is alpha
175  }
176  return 0;
177 }
178 
180  .p.name = "8bps",
181  CODEC_LONG_NAME("QuickTime 8BPS video"),
182  .p.type = AVMEDIA_TYPE_VIDEO,
183  .p.id = AV_CODEC_ID_8BPS,
184  .priv_data_size = sizeof(EightBpsContext),
185  .init = decode_init,
187  .p.capabilities = AV_CODEC_CAP_DR1,
188 };
EightBpsContext::planemap
unsigned char planemap[4]
Definition: 8bps.c:49
FF_ENABLE_DEPRECATION_WARNINGS
#define FF_ENABLE_DEPRECATION_WARNINGS
Definition: internal.h:81
AVPixelFormat
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
pixfmt_rgb24
static enum AVPixelFormat pixfmt_rgb24[]
Definition: 8bps.c:42
ff_get_format
int ff_get_format(AVCodecContext *avctx, const enum AVPixelFormat *fmt)
Select the (possibly hardware accelerated) pixel format.
Definition: decode.c:1169
decode_init
static av_cold int decode_init(AVCodecContext *avctx)
Definition: 8bps.c:140
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:330
AVPacket::data
uint8_t * data
Definition: packet.h:374
FFCodec
Definition: codec_internal.h:127
AV_PIX_FMT_BGR24
@ AV_PIX_FMT_BGR24
packed RGB 8:8:8, 24bpp, BGRBGR...
Definition: pixfmt.h:69
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:131
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
av_cold
#define av_cold
Definition: attributes.h:90
ff_eightbps_decoder
const FFCodec ff_eightbps_decoder
Definition: 8bps.c:179
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:306
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts_bsf.c:365
decode.h
EightBpsContext::avctx
AVCodecContext * avctx
Definition: 8bps.c:46
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:272
EightBpsContext::planes
unsigned char planes
Definition: 8bps.c:48
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:1506
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:375
codec_internal.h
AV_CODEC_ID_8BPS
@ AV_CODEC_ID_8BPS
Definition: codec_id.h:100
height
#define height
AV_PIX_FMT_RGB32
#define AV_PIX_FMT_RGB32
Definition: pixfmt.h:438
planes
static const struct @352 planes[]
AVCodecContext::bits_per_coded_sample
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
Definition: avcodec.h:1504
EightBpsContext
Definition: 8bps.c:45
internal.h
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:194
AVCodecContext::height
int height
Definition: avcodec.h:615
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:652
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
bswap.h
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:442
AVCodecContext
main external API structure.
Definition: avcodec.h:435
AV_PIX_FMT_NONE
@ AV_PIX_FMT_NONE
Definition: pixfmt.h:65
av_be2ne16
#define av_be2ne16(x)
Definition: bswap.h:94
FF_DISABLE_DEPRECATION_WARNINGS
#define FF_DISABLE_DEPRECATION_WARNINGS
Definition: internal.h:80
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
decode_frame
static int decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame, AVPacket *avpkt)
Definition: 8bps.c:52
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:462
AVPacket
This structure stores compressed data.
Definition: packet.h:351
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
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:1707