FFmpeg
msrle.c
Go to the documentation of this file.
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 <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 
35 #include "avcodec.h"
36 #include "decode.h"
37 #include "internal.h"
38 #include "msrledec.h"
39 #include "libavutil/imgutils.h"
40 
41 typedef struct MsrleContext {
44 
46 
47  uint32_t pal[256];
48 } MsrleContext;
49 
51 {
52  MsrleContext *s = avctx->priv_data;
53  int i;
54 
55  s->avctx = avctx;
56 
57  switch (avctx->bits_per_coded_sample) {
58  case 1:
60  break;
61  case 4:
62  case 8:
63  avctx->pix_fmt = AV_PIX_FMT_PAL8;
64  break;
65  case 24:
66  avctx->pix_fmt = AV_PIX_FMT_BGR24;
67  break;
68  default:
69  av_log(avctx, AV_LOG_ERROR, "unsupported bits per sample\n");
70  return AVERROR_INVALIDDATA;
71  }
72 
73  s->frame = av_frame_alloc();
74  if (!s->frame)
75  return AVERROR(ENOMEM);
76 
77  if (avctx->extradata_size >= 4)
78  for (i = 0; i < FFMIN(avctx->extradata_size, AVPALETTE_SIZE)/4; i++)
79  s->pal[i] = 0xFFU<<24 | AV_RL32(avctx->extradata+4*i);
80 
81  return 0;
82 }
83 
85  void *data, int *got_frame,
86  AVPacket *avpkt)
87 {
88  const uint8_t *buf = avpkt->data;
89  int buf_size = avpkt->size;
90  MsrleContext *s = avctx->priv_data;
91  int istride = FFALIGN(avctx->width*avctx->bits_per_coded_sample, 32) / 8;
92  int ret;
93 
94  if (buf_size < 2) //Minimally a end of picture code should be there
95  return AVERROR_INVALIDDATA;
96 
97  if ((ret = ff_reget_buffer(avctx, s->frame, 0)) < 0)
98  return ret;
99 
100  if (avctx->bits_per_coded_sample > 1 && avctx->bits_per_coded_sample <= 8) {
101  s->frame->palette_has_changed = ff_copy_palette(s->pal, avpkt, avctx);
102 
103  /* make the palette available */
104  memcpy(s->frame->data[1], s->pal, AVPALETTE_SIZE);
105  }
106 
107  /* FIXME how to correctly detect RLE ??? */
108  if (avctx->height * istride == avpkt->size) { /* assume uncompressed */
109  int linesize = av_image_get_linesize(avctx->pix_fmt, avctx->width, 0);
110  uint8_t *ptr = s->frame->data[0];
111  uint8_t *buf = avpkt->data + (avctx->height-1)*istride;
112  int i, j;
113 
114  if (linesize < 0)
115  return linesize;
116 
117  for (i = 0; i < avctx->height; i++) {
118  if (avctx->bits_per_coded_sample == 4) {
119  for (j = 0; j < avctx->width - 1; j += 2) {
120  ptr[j+0] = buf[j>>1] >> 4;
121  ptr[j+1] = buf[j>>1] & 0xF;
122  }
123  if (avctx->width & 1)
124  ptr[j+0] = buf[j>>1] >> 4;
125  } else {
126  memcpy(ptr, buf, linesize);
127  }
128  buf -= istride;
129  ptr += s->frame->linesize[0];
130  }
131  } else {
132  bytestream2_init(&s->gb, buf, buf_size);
133  ff_msrle_decode(avctx, s->frame, avctx->bits_per_coded_sample, &s->gb);
134  }
135 
136  if ((ret = av_frame_ref(data, s->frame)) < 0)
137  return ret;
138 
139  *got_frame = 1;
140 
141  /* report that the buffer was completely consumed */
142  return buf_size;
143 }
144 
146 {
147  MsrleContext *s = avctx->priv_data;
148 
149  av_frame_unref(s->frame);
150 }
151 
153 {
154  MsrleContext *s = avctx->priv_data;
155 
156  /* release the last frame */
157  av_frame_free(&s->frame);
158 
159  return 0;
160 }
161 
163  .name = "msrle",
164  .long_name = NULL_IF_CONFIG_SMALL("Microsoft RLE"),
165  .type = AVMEDIA_TYPE_VIDEO,
166  .id = AV_CODEC_ID_MSRLE,
167  .priv_data_size = sizeof(MsrleContext),
169  .close = msrle_decode_end,
172  .capabilities = AV_CODEC_CAP_DR1,
173  .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
174 };
AVCodec
AVCodec.
Definition: codec.h:197
FF_CODEC_CAP_INIT_THREADSAFE
#define FF_CODEC_CAP_INIT_THREADSAFE
The codec does not modify any global variables in the init function, allowing to call the init functi...
Definition: internal.h:41
init
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
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
MsrleContext::frame
AVFrame * frame
Definition: msrle.c:43
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:111
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_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
AV_PIX_FMT_BGR24
@ AV_PIX_FMT_BGR24
packed RGB 8:8:8, 24bpp, BGRBGR...
Definition: pixfmt.h:69
MsrleContext::pal
uint32_t pal[256]
Definition: msrle.c:47
msrle_decode_end
static av_cold int msrle_decode_end(AVCodecContext *avctx)
Definition: msrle.c:152
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:98
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
decode
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
AVCodecContext::extradata_size
int extradata_size
Definition: avcodec.h:603
s
#define s(width, name)
Definition: cbs_vp9.c:257
decode.h
flush
static void flush(AVCodecContext *avctx)
Definition: aacdec_template.c:592
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: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
MsrleContext::gb
GetByteContext gb
Definition: msrle.c:45
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:326
AV_CODEC_ID_MSRLE
@ AV_CODEC_ID_MSRLE
Definition: codec_id.h:94
msrle_decode_init
static av_cold int msrle_decode_init(AVCodecContext *avctx)
Definition: msrle.c:50
FFMIN
#define FFMIN(a, b)
Definition: common.h:105
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:1524
i
int i
Definition: input.c:407
AVCodecContext::extradata
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:602
MsrleContext::avctx
AVCodecContext * avctx
Definition: msrle.c:42
av_frame_unref
void av_frame_unref(AVFrame *frame)
Unreference all the buffers referenced by frame and reset the frame fields.
Definition: frame.c:436
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
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:1745
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:41
AVCodecContext
main external API structure.
Definition: avcodec.h:501
msrle_decode_flush
static void msrle_decode_flush(AVCodecContext *avctx)
Definition: msrle.c:145
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
ff_msrle_decoder
const AVCodec ff_msrle_decoder
Definition: msrle.c:162
FFALIGN
#define FFALIGN(x, a)
Definition: macros.h:48
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:342
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:528
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:674
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:28
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
msrle_decode_frame
static int msrle_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: msrle.c:84
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