FFmpeg: libavcodec/imx.c Source File
Go to the documentation of this file. 1 /*
2 * Copyright (c) 2021 Paul B Mahol
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
26
33
35 {
37
41
45
46 return 0;
47 }
48
51 {
56
59
61 frame->palette_has_changed = 1;
63 } else {
65 frame->palette_has_changed = 0;
66 }
67
69
71
72 x = 0, y = 0;
74 x < 320 && y < 160) {
75 int b = bytestream2_get_byte(&gb);
78 int fill;
79
81 case 3:
82 len =
len * 64 + bytestream2_get_byte(&gb);
83 case 0:
85 x++;
87 if (x >= 320) {
88 x = 0;
89 y++;
90 }
91 if (y >= 160)
92 break;
93 }
94
96 break;
97 case 1:
99 int offset = bytestream2_get_le16(&gb);
100
101 if (offset < 0 || offset >= 32768)
103
104 len = bytestream2_get_byte(&gb);
107 x++;
109 if (x >= 320) {
110 x = 0;
111 y++;
112 }
113 if (y >= 160)
114 break;
115 }
116
117 frame->key_frame = 0;
118 } else {
120 fill = bytestream2_get_byte(&gb);
121 frame->data[0][x + y *
frame->linesize[0]] = fill;
122 if (imx->
pos < 32768)
124 x++;
126 if (x >= 320) {
127 x = 0;
128 y++;
129 }
130 if (y >= 160)
131 break;
132 }
133 }
134 break;
135 case 2:
136 fill = bytestream2_get_byte(&gb);
137
139 frame->data[0][x + y *
frame->linesize[0]] = fill;
140 x++;
142 if (x >= 320) {
143 x = 0;
144 y++;
145 }
146 if (y >= 160)
147 break;
148 }
149 break;
150 }
151 }
152
154
157
158 *got_frame = 1;
159
161 }
162
164 {
166
169 memset(imx->
pal, 0,
sizeof(imx->
pal));
171 }
172
174 {
176
178
179 return 0;
180 }
181
183 .
name =
"simbiosis_imx",
195 };
#define FF_CODEC_CAP_INIT_THREADSAFE
The codec does not modify any global variables in the init function, allowing to call the init functi...
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 av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
This structure describes decoded (raw) audio or video data.
static void imx_decode_flush(AVCodecContext *avctx)
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
static av_cold int imx_decode_init(AVCodecContext *avctx)
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
static int op(uint8_t **dst, const uint8_t *dst_end, GetByteContext *gb, int pixel, int count, int *x, int width, int linesize)
Perform decode operation.
static int imx_decode_close(AVCodecContext *avctx)
static void flush(AVCodecContext *avctx)
@ AV_PICTURE_TYPE_I
Intra.
static av_always_inline int bytestream2_get_bytes_left(GetByteContext *g)
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
int av_frame_ref(AVFrame *dst, const AVFrame *src)
Set up a new reference to the data described by the source frame.
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 FF_CODEC_CAP_INIT_CLEANUP
The codec allows calling the close function for deallocation even if the init function returned a fai...
static int imx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
void av_frame_unref(AVFrame *frame)
Unreference all the buffers referenced by frame and reset the frame fields.
const char * name
Name of the codec implementation.
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
@ AV_PIX_FMT_PAL8
8 bits with AV_PIX_FMT_RGB32 palette
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.
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
main external API structure.
@ AV_CODEC_ID_SIMBIOSIS_IMX
@ AV_PICTURE_TYPE_P
Predicted.
const AVCodec ff_simbiosis_imx_decoder
This structure stores compressed data.
int width
picture width / height.
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
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,...
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