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ffmpeg.wasm-core
Commit bd547403 authored by Stefan Gehrer's avatar Stefan Gehrer
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add 1bpp decoding function and extend 4bpp function to 

also cover the 2bpp case.

Originally committed as revision 15242 to svn://svn.ffmpeg.org/ffmpeg/trunk
parent 31296f6e
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Showing with 89 additions and 46 deletions
libavcodec/qtrle.c
View file @ bd547403
......@@ -64,30 +64,74 @@ typedef struct QtrleContext {
static void qtrle_decode_1bpp(QtrleContext *s, int stream_ptr, int row_ptr, int lines_to_change)
{
}
int rle_code;
int pixel_ptr = 0;
int row_inc = s->frame.linesize[0];
unsigned char pi0, pi1; /* 2 8-pixel values */
unsigned char *rgb = s->frame.data[0];
int pixel_limit = s->frame.linesize[0] * s->avctx->height;
int skip;
static void qtrle_decode_2bpp(QtrleContext *s, int stream_ptr, int row_ptr, int lines_to_change)
{
while (lines_to_change) {
CHECK_STREAM_PTR(2);
skip = s->buf[stream_ptr++];
rle_code = (signed char)s->buf[stream_ptr++];
if (rle_code == 0)
break;
if(skip & 0x80) {
lines_to_change--;
row_ptr += row_inc;
pixel_ptr = row_ptr + 2 * (skip & 0x7f);
} else
pixel_ptr += 2 * skip;
CHECK_PIXEL_PTR(0); /* make sure pixel_ptr is positive */
if (rle_code < 0) {
/* decode the run length code */
rle_code = -rle_code;
/* get the next 2 bytes from the stream, treat them as groups
* of 8 pixels, and output them rle_code times */
CHECK_STREAM_PTR(2);
pi0 = s->buf[stream_ptr++];
pi1 = s->buf[stream_ptr++];
CHECK_PIXEL_PTR(rle_code * 2);
while (rle_code--) {
rgb[pixel_ptr++] = pi0;
rgb[pixel_ptr++] = pi1;
}
} else {
/* copy the same pixel directly to output 2 times */
rle_code *= 2;
CHECK_STREAM_PTR(rle_code);
CHECK_PIXEL_PTR(rle_code);
while (rle_code--)
rgb[pixel_ptr++] = s->buf[stream_ptr++];
}
}
}
static void qtrle_decode_4bpp(QtrleContext *s, int stream_ptr, int row_ptr, int lines_to_change)
static inline void qtrle_decode_2n4bpp(QtrleContext *s, int stream_ptr,
int row_ptr, int lines_to_change, int bpp)
{
int rle_code;
int rle_code, i;
int pixel_ptr;
int row_inc = s->frame.linesize[0];
unsigned char pi1, pi2, pi3, pi4, pi5, pi6, pi7, pi8; /* 8 palette indexes */
unsigned char pi[16]; /* 16 palette indices */
unsigned char *rgb = s->frame.data[0];
int pixel_limit = s->frame.linesize[0] * s->avctx->height;
int num_pixels = (bpp == 4) ? 8 : 16;
while (lines_to_change--) {
CHECK_STREAM_PTR(2);
pixel_ptr = row_ptr + (8 * (s->buf[stream_ptr++] - 1));
pixel_ptr = row_ptr + (num_pixels * (s->buf[stream_ptr++] - 1));
while ((rle_code = (signed char)s->buf[stream_ptr++]) != -1) {
if (rle_code == 0) {
/* there's another skip code in the stream */
CHECK_STREAM_PTR(1);
pixel_ptr += (8 * (s->buf[stream_ptr++] - 1));
pixel_ptr += (num_pixels * (s->buf[stream_ptr++] - 1));
CHECK_PIXEL_PTR(0); /* make sure pixel_ptr is positive */
} else if (rle_code < 0) {
/* decode the run length code */
......@@ -95,36 +139,30 @@ static void qtrle_decode_4bpp(QtrleContext *s, int stream_ptr, int row_ptr, int
/* get the next 4 bytes from the stream, treat them as palette
* indexes, and output them rle_code times */
CHECK_STREAM_PTR(4);
pi1 = ((s->buf[stream_ptr]) >> 4) & 0x0f;
pi2 = (s->buf[stream_ptr++]) & 0x0f;
pi3 = ((s->buf[stream_ptr]) >> 4) & 0x0f;
pi4 = (s->buf[stream_ptr++]) & 0x0f;
pi5 = ((s->buf[stream_ptr]) >> 4) & 0x0f;
pi6 = (s->buf[stream_ptr++]) & 0x0f;
pi7 = ((s->buf[stream_ptr]) >> 4) & 0x0f;
pi8 = (s->buf[stream_ptr++]) & 0x0f;
CHECK_PIXEL_PTR(rle_code * 8);
for (i = num_pixels-1; i >= 0; i--) {
pi[num_pixels-1-i] = (s->buf[stream_ptr] >> ((i*bpp) & 0x07)) & ((1<<bpp)-1);
stream_ptr+= ((i & ((num_pixels>>2)-1)) == 0);
}
CHECK_PIXEL_PTR(rle_code * num_pixels);
while (rle_code--) {
rgb[pixel_ptr++] = pi1;
rgb[pixel_ptr++] = pi2;
rgb[pixel_ptr++] = pi3;
rgb[pixel_ptr++] = pi4;
rgb[pixel_ptr++] = pi5;
rgb[pixel_ptr++] = pi6;
rgb[pixel_ptr++] = pi7;
rgb[pixel_ptr++] = pi8;
for (i = 0; i < num_pixels; i++)
rgb[pixel_ptr++] = pi[i];
}
} else {
/* copy the same pixel directly to output 4 times */
rle_code *= 4;
CHECK_STREAM_PTR(rle_code);
CHECK_PIXEL_PTR(rle_code*2);
CHECK_PIXEL_PTR(rle_code*(num_pixels>>2));
while (rle_code--) {
rgb[pixel_ptr++] = ((s->buf[stream_ptr]) >> 4) & 0x0f;
rgb[pixel_ptr++] = (s->buf[stream_ptr++]) & 0x0f;
if(bpp == 4) {
rgb[pixel_ptr++] = ((s->buf[stream_ptr]) >> 4) & 0x0f;
rgb[pixel_ptr++] = (s->buf[stream_ptr++]) & 0x0f;
} else {
rgb[pixel_ptr++] = ((s->buf[stream_ptr]) >> 6) & 0x03;
rgb[pixel_ptr++] = ((s->buf[stream_ptr]) >> 4) & 0x03;
rgb[pixel_ptr++] = ((s->buf[stream_ptr]) >> 2) & 0x03;
rgb[pixel_ptr++] = (s->buf[stream_ptr++]) & 0x03;
}
}
}
}
......@@ -347,10 +385,13 @@ static av_cold int qtrle_decode_init(AVCodecContext *avctx)
s->avctx = avctx;
switch (avctx->bits_per_sample) {
case 1:
case 33:
avctx->pix_fmt = PIX_FMT_MONOWHITE;
break;
case 2:
case 4:
case 8:
case 33:
case 34:
case 36:
case 40:
......@@ -387,6 +428,7 @@ static int qtrle_decode_frame(AVCodecContext *avctx,
QtrleContext *s = avctx->priv_data;
int header, start_line;
int stream_ptr, height, row_ptr;
int has_palette = 0;
s->buf = buf;
s->size = buf_size;
......@@ -432,29 +474,20 @@ static int qtrle_decode_frame(AVCodecContext *avctx,
case 2:
case 34:
qtrle_decode_2bpp(s, stream_ptr, row_ptr, height);
qtrle_decode_2n4bpp(s, stream_ptr, row_ptr, height, 2);
has_palette = 1;
break;
case 4:
case 36:
qtrle_decode_4bpp(s, stream_ptr, row_ptr, height);
/* make the palette available on the way out */
memcpy(s->frame.data[1], s->avctx->palctrl->palette, AVPALETTE_SIZE);
if (s->avctx->palctrl->palette_changed) {
s->frame.palette_has_changed = 1;
s->avctx->palctrl->palette_changed = 0;
}
qtrle_decode_2n4bpp(s, stream_ptr, row_ptr, height, 4);
has_palette = 1;
break;
case 8:
case 40:
qtrle_decode_8bpp(s, stream_ptr, row_ptr, height);
/* make the palette available on the way out */
memcpy(s->frame.data[1], s->avctx->palctrl->palette, AVPALETTE_SIZE);
if (s->avctx->palctrl->palette_changed) {
s->frame.palette_has_changed = 1;
s->avctx->palctrl->palette_changed = 0;
}
has_palette = 1;
break;
case 16:
......@@ -474,6 +507,16 @@ static int qtrle_decode_frame(AVCodecContext *avctx,
avctx->bits_per_sample);
break;
}
if(has_palette) {
/* make the palette available on the way out */
memcpy(s->frame.data[1], s->avctx->palctrl->palette, AVPALETTE_SIZE);
if (s->avctx->palctrl->palette_changed) {
s->frame.palette_has_changed = 1;
s->avctx->palctrl->palette_changed = 0;
}
}
done:
*data_size = sizeof(AVFrame);
*(AVFrame*)data = s->frame;
......
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