FFmpeg: libavcodec/xfacedec.c Source File
Go to the documentation of this file. 1 /*
2 * Copyright (c) 1990 James Ashton - Sydney University
3 * Copyright (c) 2012 Stefano Sabatini
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 * X-Face decoder, based on libcompface, by James Ashton.
25 */
26
31
33 {
36
37 /* extract the last byte into r, and shift right b by 8 bits */
39
42 pranges++;
44 }
48 }
49
51 {
59 } else {
61 if (
w & 1) bitmap[0] = 1;
62 if (
w & 2) bitmap[1] = 1;
65 }
66 }
67
69 {
72 return;
75 return;
76 default:
84 return;
85 }
86 }
87
91
93 {
97 "Size value %dx%d not supported, only accepts a size of %dx%d\n",
100 }
101 }
102
106
107 return 0;
108 }
109
112 {
117 char *buf;
119
122
123 for (
i = 0, k = 0;
i < avpkt->
size && avpkt->
data[
i];
i++) {
125
126 /* ignore invalid digits */
128 continue;
129
132 "Buffer is longer than expected, truncating at byte %d\n",
i);
133 break;
134 }
137 }
138
139 /* decode image and put it in bitmap */
151
153
154 /* convert image from 1=black 0=white bitmap to MONOWHITE */
155 buf =
frame->data[0];
158 if (k == 7) {
160 byte = k = 0;
161 } else {
162 k++;
163 byte <<= 1;
164 }
166 j = 0;
167 buf +=
frame->linesize[0];
168 }
169 }
170
171 *got_frame = 1;
172
174 }
175
185 };
#define AV_LOG_WARNING
Something somehow does not look correct.
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
void ff_big_div(BigInt *b, uint8_t a, uint8_t *r)
Divide b by a storing the result in b and the remainder in the word pointed to by r.
const FFCodec ff_xface_decoder
This structure describes decoded (raw) audio or video data.
@ AV_PIX_FMT_MONOWHITE
Y , 1bpp, 0 is white, 1 is black, in each byte pixels are ordered from the msb to the lsb.
static void pop_greys(BigInt *b, char *bitmap, int w, int h)
AVCodec p
The public AVCodec.
void ff_big_add(BigInt *b, uint8_t a)
Add a to b storing the result in b.
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
#define FF_CODEC_DECODE_CB(func)
#define CODEC_LONG_NAME(str)
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
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
int(* init)(AVBSFContext *ctx)
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_WB24 unsigned int_TMPL AV_WB16 unsigned int_TMPL byte
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf offset
#define i(width, name, range_min, range_max)
#define XFACE_FIRST_PRINT
const char * name
Name of the codec implementation.
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
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
const ProbRange ff_xface_probranges_2x2[16]
main external API structure.
const ProbRange ff_xface_probranges_per_level[4][3]
This structure stores compressed data.
int width
picture width / height.
static void decode_block(BigInt *b, char *bitmap, int w, int h, int level)
uint8_t bitmap[XFACE_PIXELS]
image used internally for decoding
void ff_xface_generate_face(uint8_t *dst, uint8_t *const src)
static av_cold int xface_decode_init(AVCodecContext *avctx)
static int xface_decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame, AVPacket *avpkt)
static int pop_integer(BigInt *b, const ProbRange *pranges)
void ff_big_mul(BigInt *b, uint8_t a)
Multiply a by b storing the result in b.
Generated on Sat Oct 18 2025 19:22:50 for FFmpeg by
doxygen
1.8.17