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49 0x0660, 0xFF00, 0xCCCC, 0xF000, 0x8888, 0x000F, 0x1111, 0xFEC8,
50 0x8CEF, 0x137F, 0xF731, 0xC800, 0x008C, 0x0013, 0x3100, 0xCC00,
51 0x00CC, 0x0033, 0x3300, 0x0FF0, 0x6666, 0x00F0, 0x0F00, 0x2222,
52 0x4444, 0xF600, 0x8CC8, 0x006F, 0x1331, 0x318C, 0xC813, 0x33CC,
53 0x6600, 0x0CC0, 0x0066, 0x0330, 0xF900, 0xC88C, 0x009F, 0x3113,
54 0x6000, 0x0880, 0x0006, 0x0110, 0xCC88, 0xFC00, 0x00CF, 0x88CC,
55 0x003F, 0x1133, 0x3311, 0xF300, 0x6FF6, 0x0603, 0x08C6, 0x8C63,
56 0xC631, 0x6310, 0xC060, 0x0136, 0x136C, 0x36C8, 0x6C80, 0x324C
63 start = bytestream2_get_byte(&
c->stream);
64 size = (bytestream2_get_byte(&
c->stream) - 1) & 0xFF;
65 if (start +
size > 255) {
69 if (
size*3+2 > data_size) {
73 for (
i = start;
i <= start +
size;
i++)
74 c->pal[
i] = 0xFFU << 24 | bytestream2_get_be24(&
c->stream);
77 static inline int check_pixel(uint8_t *buf, uint8_t *start, uint8_t *end)
79 return buf >= start && buf < end;
82 static inline int check_line(uint8_t *buf, uint8_t *start, uint8_t *end)
84 return buf >= start && (buf + 4) <= end;
91 int blk, blocks, t, blk2;
95 const int width =
c->avctx->width;
96 uint8_t *pstart =
c->prev_frame;
97 uint8_t *pend =
c->prev_frame +
width*
c->avctx->height;
104 blocks = (
c->avctx->width >> 2) * (
c->avctx->height >> 2);
112 blocktypes = bytestream2_get_byte(&
g);
114 switch (blocktypes & 0xC0) {
116 for (y = 0; y < 4; y++)
120 memset(cur + y*
width, 0, 4);
123 t = bytestream2_get_byte(&
g);
129 for (y = 0; y < 4; y++)
132 x = ((t & 0xF)^8) - 8;
133 y = ((t >> 4) ^8) - 8;
135 for (y = 0; y < 4; y++)
139 memset(cur + y*
width, 0, 4);
143 t = bytestream2_get_byte(&
g);
144 for (y = 0; y < 4; y++)
145 memset(cur + y*
width, t, 4);
148 t = bytestream2_get_byte(&
g);
153 a = bytestream2_get_byte(&
g);
154 b = bytestream2_get_byte(&
g);
155 for (y = 0; y < 4; y++)
156 for (x = 0; x < 4; x++, pattern >>= 1)
157 cur[x + y*
width] = (pattern & 1) ?
b :
a;
162 a = bytestream2_get_byte(&
g);
163 for (y = 0; y < 4; y++)
164 for (x = 0; x < 4; x++, pattern >>= 1)
180 if (blk2 == (
width >> 2)) {
193 uint8_t *outptr, *srcptr;
207 flags = bytestream2_get_le16(&
c->stream);
210 i = (int16_t)bytestream2_get_le16(&
c->stream);
211 j = (int16_t)bytestream2_get_le16(&
c->stream);
219 size = bytestream2_get_le32(&
c->stream);
228 size = bytestream2_get_le32(&
c->stream);
235 outptr =
frame->data[0];
239 memcpy(outptr, srcptr, avctx->
width);
240 srcptr += avctx->
width;
241 outptr +=
frame->linesize[0];
244 FFSWAP(uint8_t*,
c->frame,
c->prev_frame);
262 if (!
c->frame || !
c->prev_frame)
#define FF_CODEC_CAP_INIT_CLEANUP
The codec allows calling the close function for deallocation even if the init function returned a fai...
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
This structure describes decoded (raw) audio or video data.
static void vb_decode_palette(VBDecContext *c, int data_size)
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
AVCodec p
The public AVCodec.
static const uint16_t vb_patterns[64]
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
static int decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame, AVPacket *avpkt)
#define FF_CODEC_DECODE_CB(func)
int(* init)(AVBSFContext *ctx)
#define CODEC_LONG_NAME(str)
static int check_line(uint8_t *buf, uint8_t *start, uint8_t *end)
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
const FFCodec ff_vb_decoder
static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g, uint8_t *dst, unsigned int size)
static av_cold int decode_init(AVCodecContext *avctx)
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
static av_always_inline int bytestream2_get_bytes_left(GetByteContext *g)
static int check_pixel(uint8_t *buf, uint8_t *start, uint8_t *end)
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
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
uint32_t pal[AVPALETTE_COUNT]
#define i(width, name, range_min, range_max)
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
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
#define FFSWAP(type, a, b)
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
static int vb_decode_framedata(VBDecContext *c, int offset)
main external API structure.
static av_cold int decode_end(AVCodecContext *avctx)
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 flags(name, subs,...)
#define AVERROR_INVALIDDATA
Invalid data found when processing input.