ffmpeg/libavcodec/rpzaenc.c
Andreas Rheinhardt 56e9e0273a avcodec/encode: Always use intermediate buffer in ff_alloc_packet2()
Up until now, ff_alloc_packet2() has a min_size parameter:
It is supposed to be a lower bound on the final size of the packet
to allocate. If it is not too far from the upper bound (namely,
if it is at least half the upper bound), then ff_alloc_packet2()
already allocates the final, already refcounted packet; if it is
not, then the packet is not refcounted and its data only points to
a buffer owned by the AVCodecContext (in this case, the packet will
be made refcounted in encode_simple_internal() in libavcodec/encode.c).
The goal of this was to avoid data copies and intermediate buffers
if one has a precise lower bound.

Yet those encoders for which precise lower bounds exist have recently
been switched to ff_get_encode_buffer() (which automatically allocates
final buffers), leaving only two encoders to actually set the min_size
to something else than zero (namely aliaspixenc and hapenc). Both of
these encoders use a very low lower bound that is not helpful in any
nontrivial case.

This commit therefore removes the min_size parameter as well as the
codepath in ff_alloc_packet2() for the allocation of final buffers.
Furthermore, the function has been renamed to ff_alloc_packet() and
moved to encode.h alongside ff_get_encode_buffer().

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2021-06-08 12:52:50 +02:00

860 lines
26 KiB
C

/*
* QuickTime RPZA Video Encoder
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file rpzaenc.c
* QT RPZA Video Encoder by Todd Kirby <doubleshot@pacbell.net> and David Adler
*/
#include "libavutil/avassert.h"
#include "libavutil/common.h"
#include "libavutil/opt.h"
#include "avcodec.h"
#include "encode.h"
#include "internal.h"
#include "put_bits.h"
typedef struct RpzaContext {
AVClass *avclass;
int skip_frame_thresh;
int start_one_color_thresh;
int continue_one_color_thresh;
int sixteen_color_thresh;
AVFrame *prev_frame; // buffer for previous source frame
PutBitContext pb; // buffer for encoded frame data.
int frame_width; // width in pixels of source frame
int frame_height; // height in pixesl of source frame
int first_frame; // flag set to one when the first frame is being processed
// so that comparisons with previous frame data in not attempted
} RpzaContext;
typedef enum channel_offset {
RED = 2,
GREEN = 1,
BLUE = 0,
} channel_offset;
typedef struct rgb {
uint8_t r;
uint8_t g;
uint8_t b;
} rgb;
#define SQR(x) ((x) * (x))
/* 15 bit components */
#define GET_CHAN(color, chan) (((color) >> ((chan) * 5) & 0x1F) * 8)
#define R(color) GET_CHAN(color, RED)
#define G(color) GET_CHAN(color, GREEN)
#define B(color) GET_CHAN(color, BLUE)
typedef struct BlockInfo {
int row;
int col;
int block_width;
int block_height;
int image_width;
int image_height;
int block_index;
uint16_t start;
int rowstride;
int blocks_per_row;
int total_blocks;
} BlockInfo;
static void get_colors(uint8_t *min, uint8_t *max, uint8_t color4[4][3])
{
uint8_t step;
color4[0][0] = min[0];
color4[0][1] = min[1];
color4[0][2] = min[2];
color4[3][0] = max[0];
color4[3][1] = max[1];
color4[3][2] = max[2];
// red components
step = (color4[3][0] - color4[0][0] + 1) / 3;
color4[1][0] = color4[0][0] + step;
color4[2][0] = color4[3][0] - step;
// green components
step = (color4[3][1] - color4[0][1] + 1) / 3;
color4[1][1] = color4[0][1] + step;
color4[2][1] = color4[3][1] - step;
// blue components
step = (color4[3][2] - color4[0][2] + 1) / 3;
color4[1][2] = color4[0][2] + step;
color4[2][2] = color4[3][2] - step;
}
/* Fill BlockInfo struct with information about a 4x4 block of the image */
static int get_block_info(BlockInfo *bi, int block)
{
bi->row = block / bi->blocks_per_row;
bi->col = block % bi->blocks_per_row;
// test for right edge block
if (bi->col == bi->blocks_per_row - 1 && (bi->image_width % 4) != 0) {
bi->block_width = bi->image_width % 4;
} else {
bi->block_width = 4;
}
// test for bottom edge block
if (bi->row == (bi->image_height / 4) && (bi->image_height % 4) != 0) {
bi->block_height = bi->image_height % 4;
} else {
bi->block_height = 4;
}
return block ? (bi->col * 4) + (bi->row * bi->rowstride * 4) : 0;
}
static uint16_t rgb24_to_rgb555(uint8_t *rgb24)
{
uint16_t rgb555 = 0;
uint32_t r, g, b;
r = rgb24[0] >> 3;
g = rgb24[1] >> 3;
b = rgb24[2] >> 3;
rgb555 |= (r << 10);
rgb555 |= (g << 5);
rgb555 |= (b << 0);
return rgb555;
}
/*
* Returns the total difference between two 24 bit color values
*/
static int diff_colors(uint8_t *colorA, uint8_t *colorB)
{
int tot;
tot = SQR(colorA[0] - colorB[0]);
tot += SQR(colorA[1] - colorB[1]);
tot += SQR(colorA[2] - colorB[2]);
return tot;
}
/*
* Returns the maximum channel difference
*/
static int max_component_diff(uint16_t *colorA, uint16_t *colorB)
{
int diff, max = 0;
diff = FFABS(R(colorA[0]) - R(colorB[0]));
if (diff > max) {
max = diff;
}
diff = FFABS(G(colorA[0]) - G(colorB[0]));
if (diff > max) {
max = diff;
}
diff = FFABS(B(colorA[0]) - B(colorB[0]));
if (diff > max) {
max = diff;
}
return max * 8;
}
/*
* Find the channel that has the largest difference between minimum and maximum
* color values. Put the minimum value in min, maximum in max and the channel
* in chan.
*/
static void get_max_component_diff(BlockInfo *bi, uint16_t *block_ptr,
uint8_t *min, uint8_t *max, channel_offset *chan)
{
int x, y;
uint8_t min_r, max_r, min_g, max_g, min_b, max_b;
uint8_t r, g, b;
// fix warning about uninitialized vars
min_r = min_g = min_b = UINT8_MAX;
max_r = max_g = max_b = 0;
// loop thru and compare pixels
for (y = 0; y < bi->block_height; y++) {
for (x = 0; x < bi->block_width; x++){
// TODO: optimize
min_r = FFMIN(R(block_ptr[x]), min_r);
min_g = FFMIN(G(block_ptr[x]), min_g);
min_b = FFMIN(B(block_ptr[x]), min_b);
max_r = FFMAX(R(block_ptr[x]), max_r);
max_g = FFMAX(G(block_ptr[x]), max_g);
max_b = FFMAX(B(block_ptr[x]), max_b);
}
block_ptr += bi->rowstride;
}
r = max_r - min_r;
g = max_g - min_g;
b = max_b - min_b;
if (r > g && r > b) {
*max = max_r;
*min = min_r;
*chan = RED;
} else if (g > b && g >= r) {
*max = max_g;
*min = min_g;
*chan = GREEN;
} else {
*max = max_b;
*min = min_b;
*chan = BLUE;
}
}
/*
* Compare two 4x4 blocks to determine if the total difference between the
* blocks is greater than the thresh parameter. Returns -1 if difference
* exceeds threshold or zero otherwise.
*/
static int compare_blocks(uint16_t *block1, uint16_t *block2, BlockInfo *bi, int thresh)
{
int x, y, diff = 0;
for (y = 0; y < bi->block_height; y++) {
for (x = 0; x < bi->block_width; x++) {
diff = max_component_diff(&block1[x], &block2[x]);
if (diff >= thresh) {
return -1;
}
}
block1 += bi->rowstride;
block2 += bi->rowstride;
}
return 0;
}
/*
* Determine the fit of one channel to another within a 4x4 block. This
* is used to determine the best palette choices for 4-color encoding.
*/
static int leastsquares(uint16_t *block_ptr, BlockInfo *bi,
channel_offset xchannel, channel_offset ychannel,
double *slope, double *y_intercept, double *correlation_coef)
{
double sumx = 0, sumy = 0, sumx2 = 0, sumy2 = 0, sumxy = 0,
sumx_sq = 0, sumy_sq = 0, tmp, tmp2;
int i, j, count;
uint8_t x, y;
count = bi->block_height * bi->block_width;
if (count < 2)
return -1;
for (i = 0; i < bi->block_height; i++) {
for (j = 0; j < bi->block_width; j++){
x = GET_CHAN(block_ptr[j], xchannel);
y = GET_CHAN(block_ptr[j], ychannel);
sumx += x;
sumy += y;
sumx2 += x * x;
sumy2 += y * y;
sumxy += x * y;
}
block_ptr += bi->rowstride;
}
sumx_sq = sumx * sumx;
tmp = (count * sumx2 - sumx_sq);
// guard against div/0
if (tmp == 0)
return -2;
sumy_sq = sumy * sumy;
*slope = (sumx * sumy - sumxy) / tmp;
*y_intercept = (sumy - (*slope) * sumx) / count;
tmp2 = count * sumy2 - sumy_sq;
if (tmp2 == 0) {
*correlation_coef = 0.0;
} else {
*correlation_coef = (count * sumxy - sumx * sumy) /
sqrt(tmp * tmp2);
}
return 0; // success
}
/*
* Determine the amount of error in the leastsquares fit.
*/
static int calc_lsq_max_fit_error(uint16_t *block_ptr, BlockInfo *bi,
int min, int max, int tmp_min, int tmp_max,
channel_offset xchannel, channel_offset ychannel)
{
int i, j, x, y;
int err;
int max_err = 0;
for (i = 0; i < bi->block_height; i++) {
for (j = 0; j < bi->block_width; j++){
int x_inc, lin_y, lin_x;
x = GET_CHAN(block_ptr[j], xchannel);
y = GET_CHAN(block_ptr[j], ychannel);
/* calculate x_inc as the 4-color index (0..3) */
x_inc = floor( (x - min) * 3.0 / (max - min) + 0.5);
x_inc = FFMAX(FFMIN(3, x_inc), 0);
/* calculate lin_y corresponding to x_inc */
lin_y = (int)(tmp_min + (tmp_max - tmp_min) * x_inc / 3.0 + 0.5);
err = FFABS(lin_y - y);
if (err > max_err)
max_err = err;
/* calculate lin_x corresponding to x_inc */
lin_x = (int)(min + (max - min) * x_inc / 3.0 + 0.5);
err = FFABS(lin_x - x);
if (err > max_err)
max_err += err;
}
block_ptr += bi->rowstride;
}
return max_err;
}
/*
* Find the closest match to a color within the 4-color palette
*/
static int match_color(uint16_t *color, uint8_t colors[4][3])
{
int ret = 0;
int smallest_variance = INT_MAX;
uint8_t dithered_color[3];
for (int channel = 0; channel < 3; channel++) {
dithered_color[channel] = GET_CHAN(color[0], channel);
}
for (int palette_entry = 0; palette_entry < 4; palette_entry++) {
int variance = diff_colors(dithered_color, colors[palette_entry]);
if (variance < smallest_variance) {
smallest_variance = variance;
ret = palette_entry;
}
}
return ret;
}
/*
* Encode a block using the 4-color opcode and palette. return number of
* blocks encoded (until we implement multi-block 4 color runs this will
* always be 1)
*/
static int encode_four_color_block(uint8_t *min_color, uint8_t *max_color,
PutBitContext *pb, uint16_t *block_ptr, BlockInfo *bi)
{
int x, y, idx;
uint8_t color4[4][3];
uint16_t rounded_max, rounded_min;
// round min and max wider
rounded_min = rgb24_to_rgb555(min_color);
rounded_max = rgb24_to_rgb555(max_color);
// put a and b colors
// encode 4 colors = first 16 bit color with MSB zeroed and...
put_bits(pb, 16, rounded_max & ~0x8000);
// ...second 16 bit color with MSB on.
put_bits(pb, 16, rounded_min | 0x8000);
get_colors(min_color, max_color, color4);
for (y = 0; y < 4; y++) {
for (x = 0; x < 4; x++) {
idx = match_color(&block_ptr[x], color4);
put_bits(pb, 2, idx);
}
block_ptr += bi->rowstride;
}
return 1; // num blocks encoded
}
/*
* Copy a 4x4 block from the current frame buffer to the previous frame buffer.
*/
static void update_block_in_prev_frame(const uint16_t *src_pixels,
uint16_t *dest_pixels,
const BlockInfo *bi, int block_counter)
{
for (int y = 0; y < 4; y++) {
memcpy(dest_pixels, src_pixels, 8);
dest_pixels += bi->rowstride;
src_pixels += bi->rowstride;
}
}
/*
* update statistics for the specified block. If first_block,
* it initializes the statistics. Otherwise it updates the statistics IF THIS
* BLOCK IS SUITABLE TO CONTINUE A 1-COLOR RUN. That is, it checks whether
* the range of colors (since the routine was called first_block != 0) are
* all close enough intensities to be represented by a single color.
* The routine returns 0 if this block is too different to be part of
* the same run of 1-color blocks. The routine returns 1 if this
* block can be part of the same 1-color block run.
* If the routine returns 1, it also updates its arguments to include
* the statistics of this block. Otherwise, the stats are unchanged
* and don't include the current block.
*/
static int update_block_stats(RpzaContext *s, BlockInfo *bi, uint16_t *block,
uint8_t min_color[3], uint8_t max_color[3],
int *total_rgb, int *total_pixels,
uint8_t avg_color[3], int first_block)
{
int x, y;
int is_in_range;
int total_pixels_blk;
int threshold;
uint8_t min_color_blk[3], max_color_blk[3];
int total_rgb_blk[3];
uint8_t avg_color_blk[3];
if (first_block) {
min_color[0] = UINT8_MAX;
min_color[1] = UINT8_MAX;
min_color[2] = UINT8_MAX;
max_color[0] = 0;
max_color[1] = 0;
max_color[2] = 0;
total_rgb[0] = 0;
total_rgb[1] = 0;
total_rgb[2] = 0;
*total_pixels = 0;
threshold = s->start_one_color_thresh;
} else {
threshold = s->continue_one_color_thresh;
}
/*
The *_blk variables will include the current block.
Initialize them based on the blocks so far.
*/
min_color_blk[0] = min_color[0];
min_color_blk[1] = min_color[1];
min_color_blk[2] = min_color[2];
max_color_blk[0] = max_color[0];
max_color_blk[1] = max_color[1];
max_color_blk[2] = max_color[2];
total_rgb_blk[0] = total_rgb[0];
total_rgb_blk[1] = total_rgb[1];
total_rgb_blk[2] = total_rgb[2];
total_pixels_blk = *total_pixels + bi->block_height * bi->block_width;
/*
Update stats for this block's pixels
*/
for (y = 0; y < bi->block_height; y++) {
for (x = 0; x < bi->block_width; x++) {
total_rgb_blk[0] += R(block[x]);
total_rgb_blk[1] += G(block[x]);
total_rgb_blk[2] += B(block[x]);
min_color_blk[0] = FFMIN(R(block[x]), min_color_blk[0]);
min_color_blk[1] = FFMIN(G(block[x]), min_color_blk[1]);
min_color_blk[2] = FFMIN(B(block[x]), min_color_blk[2]);
max_color_blk[0] = FFMAX(R(block[x]), max_color_blk[0]);
max_color_blk[1] = FFMAX(G(block[x]), max_color_blk[1]);
max_color_blk[2] = FFMAX(B(block[x]), max_color_blk[2]);
}
block += bi->rowstride;
}
/*
Calculate average color including current block.
*/
avg_color_blk[0] = total_rgb_blk[0] / total_pixels_blk;
avg_color_blk[1] = total_rgb_blk[1] / total_pixels_blk;
avg_color_blk[2] = total_rgb_blk[2] / total_pixels_blk;
/*
Are all the pixels within threshold of the average color?
*/
is_in_range = (max_color_blk[0] - avg_color_blk[0] <= threshold &&
max_color_blk[1] - avg_color_blk[1] <= threshold &&
max_color_blk[2] - avg_color_blk[2] <= threshold &&
avg_color_blk[0] - min_color_blk[0] <= threshold &&
avg_color_blk[1] - min_color_blk[1] <= threshold &&
avg_color_blk[2] - min_color_blk[2] <= threshold);
if (is_in_range) {
/*
Set the output variables to include this block.
*/
min_color[0] = min_color_blk[0];
min_color[1] = min_color_blk[1];
min_color[2] = min_color_blk[2];
max_color[0] = max_color_blk[0];
max_color[1] = max_color_blk[1];
max_color[2] = max_color_blk[2];
total_rgb[0] = total_rgb_blk[0];
total_rgb[1] = total_rgb_blk[1];
total_rgb[2] = total_rgb_blk[2];
*total_pixels = total_pixels_blk;
avg_color[0] = avg_color_blk[0];
avg_color[1] = avg_color_blk[1];
avg_color[2] = avg_color_blk[2];
}
return is_in_range;
}
static void rpza_encode_stream(RpzaContext *s, const AVFrame *pict)
{
BlockInfo bi;
int block_counter = 0;
int n_blocks;
int total_blocks;
int prev_block_offset;
int block_offset = 0;
uint8_t min = 0, max = 0;
channel_offset chan;
int i;
int tmp_min, tmp_max;
int total_rgb[3];
uint8_t avg_color[3];
int pixel_count;
uint8_t min_color[3], max_color[3];
double slope, y_intercept, correlation_coef;
uint16_t *src_pixels = (uint16_t *)pict->data[0];
uint16_t *prev_pixels = (uint16_t *)s->prev_frame->data[0];
/* Number of 4x4 blocks in frame. */
total_blocks = ((s->frame_width + 3) / 4) * ((s->frame_height + 3) / 4);
bi.image_width = s->frame_width;
bi.image_height = s->frame_height;
bi.rowstride = pict->linesize[0] / 2;
bi.blocks_per_row = (s->frame_width + 3) / 4;
while (block_counter < total_blocks) {
// SKIP CHECK
// make sure we have a valid previous frame and we're not writing
// a key frame
if (!s->first_frame) {
n_blocks = 0;
prev_block_offset = 0;
while (n_blocks < 32 && block_counter + n_blocks < total_blocks) {
block_offset = get_block_info(&bi, block_counter + n_blocks);
// multi-block opcodes cannot span multiple rows.
// If we're starting a new row, break out and write the opcode
/* TODO: Should eventually use bi.row here to determine when a
row break occurs, but that is currently breaking the
quicktime player. This is probably due to a bug in the
way I'm calculating the current row.
*/
if (prev_block_offset && block_offset - prev_block_offset > 12) {
break;
}
prev_block_offset = block_offset;
if (compare_blocks(&prev_pixels[block_offset],
&src_pixels[block_offset], &bi, s->skip_frame_thresh) != 0) {
// write out skipable blocks
if (n_blocks) {
// write skip opcode
put_bits(&s->pb, 8, 0x80 | (n_blocks - 1));
block_counter += n_blocks;
goto post_skip;
}
break;
}
/*
* NOTE: we don't update skipped blocks in the previous frame buffer
* since skipped needs always to be compared against the first skipped
* block to avoid artifacts during gradual fade in/outs.
*/
// update_block_in_prev_frame(&src_pixels[block_offset],
// &prev_pixels[block_offset], &bi, block_counter + n_blocks);
n_blocks++;
}
// we're either at the end of the frame or we've reached the maximum
// of 32 blocks in a run. Write out the run.
if (n_blocks) {
// write skip opcode
put_bits(&s->pb, 8, 0x80 | (n_blocks - 1));
block_counter += n_blocks;
continue;
}
} else {
block_offset = get_block_info(&bi, block_counter);
}
post_skip :
// ONE COLOR CHECK
if (update_block_stats(s, &bi, &src_pixels[block_offset],
min_color, max_color,
total_rgb, &pixel_count, avg_color, 1)) {
prev_block_offset = block_offset;
n_blocks = 1;
/* update this block in the previous frame buffer */
update_block_in_prev_frame(&src_pixels[block_offset],
&prev_pixels[block_offset], &bi, block_counter + n_blocks);
// check for subsequent blocks with the same color
while (n_blocks < 32 && block_counter + n_blocks < total_blocks) {
block_offset = get_block_info(&bi, block_counter + n_blocks);
// multi-block opcodes cannot span multiple rows.
// If we've hit end of a row, break out and write the opcode
if (block_offset - prev_block_offset > 12) {
break;
}
if (!update_block_stats(s, &bi, &src_pixels[block_offset],
min_color, max_color,
total_rgb, &pixel_count, avg_color, 0)) {
break;
}
prev_block_offset = block_offset;
/* update this block in the previous frame buffer */
update_block_in_prev_frame(&src_pixels[block_offset],
&prev_pixels[block_offset], &bi, block_counter + n_blocks);
n_blocks++;
}
// write one color opcode.
put_bits(&s->pb, 8, 0xa0 | (n_blocks - 1));
// write color to encode.
put_bits(&s->pb, 16, rgb24_to_rgb555(avg_color));
// skip past the blocks we've just encoded.
block_counter += n_blocks;
} else { // FOUR COLOR CHECK
int err = 0;
// get max component diff for block
get_max_component_diff(&bi, &src_pixels[block_offset], &min, &max, &chan);
min_color[0] = 0;
max_color[0] = 0;
min_color[1] = 0;
max_color[1] = 0;
min_color[2] = 0;
max_color[2] = 0;
// run least squares against other two components
for (i = 0; i < 3; i++) {
if (i == chan) {
min_color[i] = min;
max_color[i] = max;
continue;
}
slope = y_intercept = correlation_coef = 0;
if (leastsquares(&src_pixels[block_offset], &bi, chan, i,
&slope, &y_intercept, &correlation_coef)) {
min_color[i] = GET_CHAN(src_pixels[block_offset], i);
max_color[i] = GET_CHAN(src_pixels[block_offset], i);
} else {
tmp_min = (int)(0.5 + min * slope + y_intercept);
tmp_max = (int)(0.5 + max * slope + y_intercept);
av_assert0(tmp_min <= tmp_max);
// clamp min and max color values
tmp_min = av_clip_uint8(tmp_min);
tmp_max = av_clip_uint8(tmp_max);
err = FFMAX(calc_lsq_max_fit_error(&src_pixels[block_offset], &bi,
min, max, tmp_min, tmp_max, chan, i), err);
min_color[i] = tmp_min;
max_color[i] = tmp_max;
}
}
if (err > s->sixteen_color_thresh) { // DO SIXTEEN COLOR BLOCK
uint16_t *row_ptr;
int rgb555;
block_offset = get_block_info(&bi, block_counter);
row_ptr = &src_pixels[block_offset];
for (int y = 0; y < 4; y++) {
for (int x = 0; x < 4; x++){
rgb555 = row_ptr[x] & ~0x8000;
put_bits(&s->pb, 16, rgb555);
}
row_ptr += bi.rowstride;
}
block_counter++;
} else { // FOUR COLOR BLOCK
block_counter += encode_four_color_block(min_color, max_color,
&s->pb, &src_pixels[block_offset], &bi);
}
/* update this block in the previous frame buffer */
update_block_in_prev_frame(&src_pixels[block_offset],
&prev_pixels[block_offset], &bi, block_counter);
}
}
}
static int rpza_encode_init(AVCodecContext *avctx)
{
RpzaContext *s = avctx->priv_data;
s->frame_width = avctx->width;
s->frame_height = avctx->height;
s->prev_frame = av_frame_alloc();
if (!s->prev_frame)
return AVERROR(ENOMEM);
return 0;
}
static int rpza_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
const AVFrame *frame, int *got_packet)
{
RpzaContext *s = avctx->priv_data;
const AVFrame *pict = frame;
uint8_t *buf;
int ret = ff_alloc_packet(avctx, pkt, 6LL * avctx->height * avctx->width);
if (ret < 0)
return ret;
init_put_bits(&s->pb, pkt->data, pkt->size);
// skip 4 byte header, write it later once the size of the chunk is known
put_bits32(&s->pb, 0x00);
if (!s->prev_frame->data[0]) {
s->first_frame = 1;
s->prev_frame->format = pict->format;
s->prev_frame->width = pict->width;
s->prev_frame->height = pict->height;
ret = av_frame_get_buffer(s->prev_frame, 0);
if (ret < 0)
return ret;
} else {
s->first_frame = 0;
}
rpza_encode_stream(s, pict);
flush_put_bits(&s->pb);
av_shrink_packet(pkt, put_bytes_output(&s->pb));
buf = pkt->data;
// write header opcode
buf[0] = 0xe1; // chunk opcode
// write chunk length
AV_WB24(buf + 1, pkt->size);
*got_packet = 1;
return 0;
}
static int rpza_encode_end(AVCodecContext *avctx)
{
RpzaContext *s = (RpzaContext *)avctx->priv_data;
av_frame_free(&s->prev_frame);
return 0;
}
#define OFFSET(x) offsetof(RpzaContext, x)
#define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
static const AVOption options[] = {
{ "skip_frame_thresh", NULL, OFFSET(skip_frame_thresh), AV_OPT_TYPE_INT, {.i64=1}, 0, 24, VE},
{ "start_one_color_thresh", NULL, OFFSET(start_one_color_thresh), AV_OPT_TYPE_INT, {.i64=1}, 0, 24, VE},
{ "continue_one_color_thresh", NULL, OFFSET(continue_one_color_thresh), AV_OPT_TYPE_INT, {.i64=0}, 0, 24, VE},
{ "sixteen_color_thresh", NULL, OFFSET(sixteen_color_thresh), AV_OPT_TYPE_INT, {.i64=1}, 0, 24, VE},
{ NULL },
};
static const AVClass rpza_class = {
.class_name = "rpza",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
const AVCodec ff_rpza_encoder = {
.name = "rpza",
.long_name = NULL_IF_CONFIG_SMALL("QuickTime video (RPZA)"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_RPZA,
.priv_data_size = sizeof(RpzaContext),
.priv_class = &rpza_class,
.init = rpza_encode_init,
.encode2 = rpza_encode_frame,
.close = rpza_encode_end,
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
.pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_RGB555,
AV_PIX_FMT_NONE},
};