FFmpeg
msrle.c
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1 /*
2  * Microsoft RLE video decoder
3  * Copyright (C) 2003 The FFmpeg project
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  * MS RLE video decoder by Mike Melanson (melanson@pcisys.net)
25  * For more information about the MS RLE format, visit:
26  * http://www.pcisys.net/~melanson/codecs/
27  *
28  * The MS RLE decoder outputs PAL8 colorspace data.
29  */
30 
31 #include <string.h>
32 
33 #include "avcodec.h"
34 #include "codec_internal.h"
35 #include "decode.h"
36 #include "msrledec.h"
37 #include "libavutil/imgutils.h"
38 
39 typedef struct MsrleContext {
42 
44 
45  uint32_t pal[256];
46 } MsrleContext;
47 
49 {
50  MsrleContext *s = avctx->priv_data;
51  int i;
52 
53  s->avctx = avctx;
54 
55  switch (avctx->bits_per_coded_sample) {
56  case 1:
58  break;
59  case 4:
60  case 8:
61  avctx->pix_fmt = AV_PIX_FMT_PAL8;
62  break;
63  case 24:
64  avctx->pix_fmt = AV_PIX_FMT_BGR24;
65  break;
66  default:
67  av_log(avctx, AV_LOG_ERROR, "unsupported bits per sample\n");
68  return AVERROR_INVALIDDATA;
69  }
70 
71  s->frame = av_frame_alloc();
72  if (!s->frame)
73  return AVERROR(ENOMEM);
74 
75  if (avctx->extradata_size >= 4)
76  for (i = 0; i < FFMIN(avctx->extradata_size, AVPALETTE_SIZE)/4; i++)
77  s->pal[i] = 0xFFU<<24 | AV_RL32(avctx->extradata+4*i);
78 
79  return 0;
80 }
81 
82 static int msrle_decode_frame(AVCodecContext *avctx, AVFrame *rframe,
83  int *got_frame, AVPacket *avpkt)
84 {
85  const uint8_t *buf = avpkt->data;
86  int buf_size = avpkt->size;
87  MsrleContext *s = avctx->priv_data;
88  int istride = FFALIGN(avctx->width*avctx->bits_per_coded_sample, 32) / 8;
89  int ret;
90 
91  if (buf_size < 2) //Minimally a end of picture code should be there
92  return AVERROR_INVALIDDATA;
93 
94  if ((ret = ff_reget_buffer(avctx, s->frame, 0)) < 0)
95  return ret;
96 
97  if (avctx->bits_per_coded_sample > 1 && avctx->bits_per_coded_sample <= 8) {
98  s->frame->palette_has_changed = ff_copy_palette(s->pal, avpkt, avctx);
99 
100  /* make the palette available */
101  memcpy(s->frame->data[1], s->pal, AVPALETTE_SIZE);
102  }
103 
104  /* FIXME how to correctly detect RLE ??? */
105  if (avctx->height * istride == avpkt->size) { /* assume uncompressed */
106  int linesize = av_image_get_linesize(avctx->pix_fmt, avctx->width, 0);
107  uint8_t *ptr = s->frame->data[0];
108  const uint8_t *buf = avpkt->data + (avctx->height-1)*istride;
109  int i, j;
110 
111  if (linesize < 0)
112  return linesize;
113 
114  for (i = 0; i < avctx->height; i++) {
115  if (avctx->bits_per_coded_sample == 4) {
116  for (j = 0; j < avctx->width - 1; j += 2) {
117  ptr[j+0] = buf[j>>1] >> 4;
118  ptr[j+1] = buf[j>>1] & 0xF;
119  }
120  if (avctx->width & 1)
121  ptr[j+0] = buf[j>>1] >> 4;
122  } else {
123  memcpy(ptr, buf, linesize);
124  }
125  buf -= istride;
126  ptr += s->frame->linesize[0];
127  }
128  } else {
129  bytestream2_init(&s->gb, buf, buf_size);
130  ff_msrle_decode(avctx, s->frame, avctx->bits_per_coded_sample, &s->gb);
131  }
132 
133  if ((ret = av_frame_ref(rframe, s->frame)) < 0)
134  return ret;
135 
136  *got_frame = 1;
137 
138  /* report that the buffer was completely consumed */
139  return buf_size;
140 }
141 
143 {
144  MsrleContext *s = avctx->priv_data;
145 
146  av_frame_unref(s->frame);
147 }
148 
150 {
151  MsrleContext *s = avctx->priv_data;
152 
153  /* release the last frame */
154  av_frame_free(&s->frame);
155 
156  return 0;
157 }
158 
160  .p.name = "msrle",
161  CODEC_LONG_NAME("Microsoft RLE"),
162  .p.type = AVMEDIA_TYPE_VIDEO,
163  .p.id = AV_CODEC_ID_MSRLE,
164  .priv_data_size = sizeof(MsrleContext),
166  .close = msrle_decode_end,
168  .flush = msrle_decode_flush,
169  .p.capabilities = AV_CODEC_CAP_DR1,
170 };
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
GetByteContext
Definition: bytestream.h:33
msrle_decode_frame
static int msrle_decode_frame(AVCodecContext *avctx, AVFrame *rframe, int *got_frame, AVPacket *avpkt)
Definition: msrle.c:82
MsrleContext::frame
AVFrame * frame
Definition: msrle.c:41
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:116
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
AVPacket::data
uint8_t * data
Definition: packet.h:374
AV_PIX_FMT_MONOWHITE
@ AV_PIX_FMT_MONOWHITE
Y , 1bpp, 0 is white, 1 is black, in each byte pixels are ordered from the msb to the lsb.
Definition: pixfmt.h:75
FFCodec
Definition: codec_internal.h:119
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:123
MsrleContext::pal
uint32_t pal[256]
Definition: msrle.c:45
msrle_decode_end
static av_cold int msrle_decode_end(AVCodecContext *avctx)
Definition: msrle.c:149
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:104
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
AVCodecContext::extradata_size
int extradata_size
Definition: avcodec.h:500
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:298
s
#define s(width, name)
Definition: cbs_vp9.c:256
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts_bsf.c:363
decode.h
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:264
msrledec.h
AVPALETTE_SIZE
#define AVPALETTE_SIZE
Definition: pixfmt.h:32
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
MsrleContext::gb
GetByteContext gb
Definition: msrle.c:43
av_frame_ref
int av_frame_ref(AVFrame *dst, const AVFrame *src)
Set up a new reference to the data described by the source frame.
Definition: frame.c:353
codec_internal.h
ff_msrle_decoder
const FFCodec ff_msrle_decoder
Definition: msrle.c:159
AV_CODEC_ID_MSRLE
@ AV_CODEC_ID_MSRLE
Definition: codec_id.h:97
msrle_decode_init
static av_cold int msrle_decode_init(AVCodecContext *avctx)
Definition: msrle.c:48
av_image_get_linesize
int av_image_get_linesize(enum AVPixelFormat pix_fmt, int width, int plane)
Compute the size of an image line with format pix_fmt and width width for the plane plane.
Definition: imgutils.c:76
AVCodecContext::bits_per_coded_sample
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
Definition: avcodec.h:1444
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
AVCodecContext::extradata
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:499
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
MsrleContext::avctx
AVCodecContext * avctx
Definition: msrle.c:40
av_frame_unref
void av_frame_unref(AVFrame *frame)
Unreference all the buffers referenced by frame and reset the frame fields.
Definition: frame.c:487
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:211
AVCodecContext::height
int height
Definition: avcodec.h:571
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:608
avcodec.h
AV_PIX_FMT_PAL8
@ AV_PIX_FMT_PAL8
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:77
ff_reget_buffer
int ff_reget_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Identical in function to ff_get_buffer(), except it reuses the existing buffer if available.
Definition: decode.c:1538
ret
ret
Definition: filter_design.txt:187
AV_RL32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:92
MsrleContext
Definition: msrle.c:39
AVCodecContext
main external API structure.
Definition: avcodec.h:398
msrle_decode_flush
static void msrle_decode_flush(AVCodecContext *avctx)
Definition: msrle.c:142
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
FFALIGN
#define FFALIGN(x, a)
Definition: macros.h:78
ff_msrle_decode
int ff_msrle_decode(AVCodecContext *avctx, AVFrame *pic, int depth, GetByteContext *gb)
Decode stream in MS RLE format into frame.
Definition: msrledec.c:249
AVPacket
This structure stores compressed data.
Definition: packet.h:351
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:425
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:571
imgutils.h
bytestream2_init
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:137
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:1634