diff options
Diffstat (limited to 'libavcodec/flashsv2enc.c')
| -rw-r--r-- | libavcodec/flashsv2enc.c | 920 |
1 files changed, 920 insertions, 0 deletions
diff --git a/libavcodec/flashsv2enc.c b/libavcodec/flashsv2enc.c new file mode 100644 index 0000000..a8bcaa2 --- /dev/null +++ b/libavcodec/flashsv2enc.c @@ -0,0 +1,920 @@ +/* + * Flash Screen Video Version 2 encoder + * Copyright (C) 2009 Joshua Warner + * + * 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 + * Flash Screen Video Version 2 encoder + * @author Joshua Warner + */ + +/* Differences from version 1 stream: + * NOTE: Currently, the only player that supports version 2 streams is Adobe Flash Player itself. + * * Supports sending only a range of scanlines in a block, + * indicating a difference from the corresponding block in the last keyframe. + * * Supports initializing the zlib dictionary with data from the corresponding + * block in the last keyframe, to improve compression. + * * Supports a hybrid 15-bit rgb / 7-bit palette color space. + */ + +/* TODO: + * Don't keep Block structures for both current frame and keyframe. + * Make better heuristics for deciding stream parameters (optimum_* functions). Currently these return constants. + * Figure out how to encode palette information in the stream, choose an optimum palette at each keyframe. + * Figure out how the zlibPrimeCompressCurrent flag works, implement support. + * Find other sample files (that weren't generated here), develop a decoder. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <zlib.h> + +#include "libavutil/imgutils.h" +#include "avcodec.h" +#include "internal.h" +#include "put_bits.h" +#include "bytestream.h" + +#define HAS_IFRAME_IMAGE 0x02 +#define HAS_PALLET_INFO 0x01 + +#define COLORSPACE_BGR 0x00 +#define COLORSPACE_15_7 0x10 +#define HAS_DIFF_BLOCKS 0x04 +#define ZLIB_PRIME_COMPRESS_CURRENT 0x02 +#define ZLIB_PRIME_COMPRESS_PREVIOUS 0x01 + +// Disables experimental "smart" parameter-choosing code, as well as the statistics that it depends on. +// At the moment, the "smart" code is a great example of how the parameters *shouldn't* be chosen. +#define FLASHSV2_DUMB + +typedef struct Block { + uint8_t *enc; + uint8_t *sl_begin, *sl_end; + int enc_size; + uint8_t *data; + unsigned long data_size; + + uint8_t start, len; + uint8_t dirty; + uint8_t col, row, width, height; + uint8_t flags; +} Block; + +typedef struct Palette { + unsigned colors[128]; + uint8_t index[1 << 15]; +} Palette; + +typedef struct FlashSV2Context { + AVCodecContext *avctx; + uint8_t *current_frame; + uint8_t *key_frame; + uint8_t *encbuffer; + uint8_t *keybuffer; + uint8_t *databuffer; + + uint8_t *blockbuffer; + int blockbuffer_size; + + Block *frame_blocks; + Block *key_blocks; + int frame_size; + int blocks_size; + + int use15_7, dist, comp; + + int rows, cols; + + int last_key_frame; + + int image_width, image_height; + int block_width, block_height; + uint8_t flags; + uint8_t use_custom_palette; + uint8_t palette_type; ///< 0=>default, 1=>custom - changed when palette regenerated. + Palette palette; +#ifndef FLASHSV2_DUMB + double tot_blocks; ///< blocks encoded since last keyframe + double diff_blocks; ///< blocks that were different since last keyframe + double tot_lines; ///< total scanlines in image since last keyframe + double diff_lines; ///< scanlines that were different since last keyframe + double raw_size; ///< size of raw frames since last keyframe + double comp_size; ///< size of compressed data since last keyframe + double uncomp_size; ///< size of uncompressed data since last keyframe + + double total_bits; ///< total bits written to stream so far +#endif +} FlashSV2Context; + +static av_cold void cleanup(FlashSV2Context * s) +{ + av_freep(&s->encbuffer); + av_freep(&s->keybuffer); + av_freep(&s->databuffer); + av_freep(&s->blockbuffer); + av_freep(&s->current_frame); + av_freep(&s->key_frame); + + av_freep(&s->frame_blocks); + av_freep(&s->key_blocks); +} + +static void init_blocks(FlashSV2Context * s, Block * blocks, + uint8_t * encbuf, uint8_t * databuf) +{ + int row, col; + Block *b; + for (col = 0; col < s->cols; col++) { + for (row = 0; row < s->rows; row++) { + b = blocks + (col + row * s->cols); + b->width = (col < s->cols - 1) ? + s->block_width : + s->image_width - col * s->block_width; + + b->height = (row < s->rows - 1) ? + s->block_height : + s->image_height - row * s->block_height; + + b->row = row; + b->col = col; + b->enc = encbuf; + b->data = databuf; + encbuf += b->width * b->height * 3; + databuf += !databuf ? 0 : b->width * b->height * 6; + } + } +} + +static void reset_stats(FlashSV2Context * s) +{ +#ifndef FLASHSV2_DUMB + s->diff_blocks = 0.1; + s->tot_blocks = 1; + s->diff_lines = 0.1; + s->tot_lines = 1; + s->raw_size = s->comp_size = s->uncomp_size = 10; +#endif +} + +static av_cold int flashsv2_encode_init(AVCodecContext * avctx) +{ + FlashSV2Context *s = avctx->priv_data; + + s->avctx = avctx; + + s->comp = avctx->compression_level; + if (s->comp == -1) + s->comp = 9; + if (s->comp < 0 || s->comp > 9) { + av_log(avctx, AV_LOG_ERROR, + "Compression level should be 0-9, not %d\n", s->comp); + return -1; + } + + + if ((avctx->width > 4095) || (avctx->height > 4095)) { + av_log(avctx, AV_LOG_ERROR, + "Input dimensions too large, input must be max 4095x4095 !\n"); + return -1; + } + if ((avctx->width < 16) || (avctx->height < 16)) { + av_log(avctx, AV_LOG_ERROR, + "Input dimensions too small, input must be at least 16x16 !\n"); + return -1; + } + + if (av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) + return -1; + + + s->last_key_frame = 0; + + s->image_width = avctx->width; + s->image_height = avctx->height; + + s->block_width = (s->image_width / 12) & ~15; + s->block_height = (s->image_height / 12) & ~15; + + if(!s->block_width) + s->block_width = 1; + if(!s->block_height) + s->block_height = 1; + + s->rows = (s->image_height + s->block_height - 1) / s->block_height; + s->cols = (s->image_width + s->block_width - 1) / s->block_width; + + s->frame_size = s->image_width * s->image_height * 3; + s->blocks_size = s->rows * s->cols * sizeof(Block); + + s->encbuffer = av_mallocz(s->frame_size); + s->keybuffer = av_mallocz(s->frame_size); + s->databuffer = av_mallocz(s->frame_size * 6); + s->current_frame = av_mallocz(s->frame_size); + s->key_frame = av_mallocz(s->frame_size); + s->frame_blocks = av_mallocz(s->blocks_size); + s->key_blocks = av_mallocz(s->blocks_size); + + s->blockbuffer = NULL; + s->blockbuffer_size = 0; + + init_blocks(s, s->frame_blocks, s->encbuffer, s->databuffer); + init_blocks(s, s->key_blocks, s->keybuffer, 0); + reset_stats(s); +#ifndef FLASHSV2_DUMB + s->total_bits = 1; +#endif + + s->use_custom_palette = 0; + s->palette_type = -1; // so that the palette will be generated in reconfigure_at_keyframe + + if (!s->encbuffer || !s->keybuffer || !s->databuffer + || !s->current_frame || !s->key_frame || !s->key_blocks + || !s->frame_blocks) { + av_log(avctx, AV_LOG_ERROR, "Memory allocation failed.\n"); + cleanup(s); + return -1; + } + + return 0; +} + +static int new_key_frame(FlashSV2Context * s) +{ + int i; + memcpy(s->key_blocks, s->frame_blocks, s->blocks_size); + memcpy(s->key_frame, s->current_frame, s->frame_size); + + for (i = 0; i < s->rows * s->cols; i++) { + s->key_blocks[i].enc += (s->keybuffer - s->encbuffer); + s->key_blocks[i].sl_begin = 0; + s->key_blocks[i].sl_end = 0; + s->key_blocks[i].data = 0; + } + memcpy(s->keybuffer, s->encbuffer, s->frame_size); + + return 0; +} + +static int write_palette(FlashSV2Context * s, uint8_t * buf, int buf_size) +{ + //this isn't implemented yet! Default palette only! + return -1; +} + +static int write_header(FlashSV2Context * s, uint8_t * buf, int buf_size) +{ + PutBitContext pb; + int buf_pos, len; + + if (buf_size < 5) + return -1; + + init_put_bits(&pb, buf, buf_size); + + put_bits(&pb, 4, (s->block_width >> 4) - 1); + put_bits(&pb, 12, s->image_width); + put_bits(&pb, 4, (s->block_height >> 4) - 1); + put_bits(&pb, 12, s->image_height); + + flush_put_bits(&pb); + buf_pos = 4; + + buf[buf_pos++] = s->flags; + + if (s->flags & HAS_PALLET_INFO) { + len = write_palette(s, buf + buf_pos, buf_size - buf_pos); + if (len < 0) + return -1; + buf_pos += len; + } + + return buf_pos; +} + +static int write_block(Block * b, uint8_t * buf, int buf_size) +{ + int buf_pos = 0; + unsigned block_size = b->data_size; + + if (b->flags & HAS_DIFF_BLOCKS) + block_size += 2; + if (b->flags & ZLIB_PRIME_COMPRESS_CURRENT) + block_size += 2; + if (block_size > 0) + block_size += 1; + if (buf_size < block_size + 2) + return -1; + + buf[buf_pos++] = block_size >> 8; + buf[buf_pos++] = block_size; + + if (block_size == 0) + return buf_pos; + + buf[buf_pos++] = b->flags; + + if (b->flags & HAS_DIFF_BLOCKS) { + buf[buf_pos++] = (b->start); + buf[buf_pos++] = (b->len); + } + + if (b->flags & ZLIB_PRIME_COMPRESS_CURRENT) { + //This feature of the format is poorly understood, and as of now, unused. + buf[buf_pos++] = (b->col); + buf[buf_pos++] = (b->row); + } + + memcpy(buf + buf_pos, b->data, b->data_size); + + buf_pos += b->data_size; + + return buf_pos; +} + +static int encode_zlib(Block * b, uint8_t * buf, unsigned long *buf_size, int comp) +{ + int res = compress2(buf, buf_size, b->sl_begin, b->sl_end - b->sl_begin, comp); + return res == Z_OK ? 0 : -1; +} + +static int encode_zlibprime(Block * b, Block * prime, uint8_t * buf, + int *buf_size, int comp) +{ + z_stream s; + int res; + s.zalloc = NULL; + s.zfree = NULL; + s.opaque = NULL; + res = deflateInit(&s, comp); + if (res < 0) + return -1; + + s.next_in = prime->enc; + s.avail_in = prime->enc_size; + while (s.avail_in > 0) { + s.next_out = buf; + s.avail_out = *buf_size; + res = deflate(&s, Z_SYNC_FLUSH); + if (res < 0) + return -1; + } + + s.next_in = b->sl_begin; + s.avail_in = b->sl_end - b->sl_begin; + s.next_out = buf; + s.avail_out = *buf_size; + res = deflate(&s, Z_FINISH); + deflateEnd(&s); + *buf_size -= s.avail_out; + if (res != Z_STREAM_END) + return -1; + return 0; +} + +static int encode_bgr(Block * b, const uint8_t * src, int stride) +{ + int i; + uint8_t *ptr = b->enc; + for (i = 0; i < b->start; i++) + memcpy(ptr + i * b->width * 3, src + i * stride, b->width * 3); + b->sl_begin = ptr + i * b->width * 3; + for (; i < b->start + b->len; i++) + memcpy(ptr + i * b->width * 3, src + i * stride, b->width * 3); + b->sl_end = ptr + i * b->width * 3; + for (; i < b->height; i++) + memcpy(ptr + i * b->width * 3, src + i * stride, b->width * 3); + b->enc_size = ptr + i * b->width * 3 - b->enc; + return b->enc_size; +} + +static inline unsigned pixel_color15(const uint8_t * src) +{ + return (src[0] >> 3) | ((src[1] & 0xf8) << 2) | ((src[2] & 0xf8) << 7); +} + +static inline unsigned int chroma_diff(unsigned int c1, unsigned int c2) +{ + unsigned int t1 = (c1 & 0x000000ff) + ((c1 & 0x0000ff00) >> 8) + ((c1 & 0x00ff0000) >> 16); + unsigned int t2 = (c2 & 0x000000ff) + ((c2 & 0x0000ff00) >> 8) + ((c2 & 0x00ff0000) >> 16); + + return abs(t1 - t2) + abs((c1 & 0x000000ff) - (c2 & 0x000000ff)) + + abs(((c1 & 0x0000ff00) >> 8) - ((c2 & 0x0000ff00) >> 8)) + + abs(((c1 & 0x00ff0000) >> 16) - ((c2 & 0x00ff0000) >> 16)); +} + +static inline int pixel_color7_fast(Palette * palette, unsigned c15) +{ + return palette->index[c15]; +} + +static int pixel_color7_slow(Palette * palette, unsigned color) +{ + int i, min = 0x7fffffff; + int minc = -1; + for (i = 0; i < 128; i++) { + int c1 = palette->colors[i]; + int diff = chroma_diff(c1, color); + if (diff < min) { + min = diff; + minc = i; + } + } + return minc; +} + +static inline unsigned pixel_bgr(const uint8_t * src) +{ + return (src[0]) | (src[1] << 8) | (src[2] << 16); +} + +static int write_pixel_15_7(Palette * palette, uint8_t * dest, const uint8_t * src, + int dist) +{ + unsigned c15 = pixel_color15(src); + unsigned color = pixel_bgr(src); + int d15 = chroma_diff(color, color & 0x00f8f8f8); + int c7 = pixel_color7_fast(palette, c15); + int d7 = chroma_diff(color, palette->colors[c7]); + if (dist + d15 >= d7) { + dest[0] = c7; + return 1; + } else { + dest[0] = 0x80 | (c15 >> 8); + dest[1] = c15 & 0xff; + return 2; + } +} + +static int update_palette_index(Palette * palette) +{ + int r, g, b; + unsigned int bgr, c15, index; + for (r = 4; r < 256; r += 8) { + for (g = 4; g < 256; g += 8) { + for (b = 4; b < 256; b += 8) { + bgr = b | (g << 8) | (r << 16); + c15 = (b >> 3) | ((g & 0xf8) << 2) | ((r & 0xf8) << 7); + index = pixel_color7_slow(palette, bgr); + + palette->index[c15] = index; + } + } + } + return 0; +} + +static const unsigned int default_screen_video_v2_palette[128] = { + 0x00000000, 0x00333333, 0x00666666, 0x00999999, 0x00CCCCCC, 0x00FFFFFF, + 0x00330000, 0x00660000, 0x00990000, 0x00CC0000, 0x00FF0000, 0x00003300, + 0x00006600, 0x00009900, 0x0000CC00, 0x0000FF00, 0x00000033, 0x00000066, + 0x00000099, 0x000000CC, 0x000000FF, 0x00333300, 0x00666600, 0x00999900, + 0x00CCCC00, 0x00FFFF00, 0x00003333, 0x00006666, 0x00009999, 0x0000CCCC, + 0x0000FFFF, 0x00330033, 0x00660066, 0x00990099, 0x00CC00CC, 0x00FF00FF, + 0x00FFFF33, 0x00FFFF66, 0x00FFFF99, 0x00FFFFCC, 0x00FF33FF, 0x00FF66FF, + 0x00FF99FF, 0x00FFCCFF, 0x0033FFFF, 0x0066FFFF, 0x0099FFFF, 0x00CCFFFF, + 0x00CCCC33, 0x00CCCC66, 0x00CCCC99, 0x00CCCCFF, 0x00CC33CC, 0x00CC66CC, + 0x00CC99CC, 0x00CCFFCC, 0x0033CCCC, 0x0066CCCC, 0x0099CCCC, 0x00FFCCCC, + 0x00999933, 0x00999966, 0x009999CC, 0x009999FF, 0x00993399, 0x00996699, + 0x0099CC99, 0x0099FF99, 0x00339999, 0x00669999, 0x00CC9999, 0x00FF9999, + 0x00666633, 0x00666699, 0x006666CC, 0x006666FF, 0x00663366, 0x00669966, + 0x0066CC66, 0x0066FF66, 0x00336666, 0x00996666, 0x00CC6666, 0x00FF6666, + 0x00333366, 0x00333399, 0x003333CC, 0x003333FF, 0x00336633, 0x00339933, + 0x0033CC33, 0x0033FF33, 0x00663333, 0x00993333, 0x00CC3333, 0x00FF3333, + 0x00003366, 0x00336600, 0x00660033, 0x00006633, 0x00330066, 0x00663300, + 0x00336699, 0x00669933, 0x00993366, 0x00339966, 0x00663399, 0x00996633, + 0x006699CC, 0x0099CC66, 0x00CC6699, 0x0066CC99, 0x009966CC, 0x00CC9966, + 0x0099CCFF, 0x00CCFF99, 0x00FF99CC, 0x0099FFCC, 0x00CC99FF, 0x00FFCC99, + 0x00111111, 0x00222222, 0x00444444, 0x00555555, 0x00AAAAAA, 0x00BBBBBB, + 0x00DDDDDD, 0x00EEEEEE +}; + +static int generate_default_palette(Palette * palette) +{ + memcpy(palette->colors, default_screen_video_v2_palette, + sizeof(default_screen_video_v2_palette)); + + return update_palette_index(palette); +} + +static int generate_optimum_palette(Palette * palette, const uint8_t * image, + int width, int height, int stride) +{ + //this isn't implemented yet! Default palette only! + return -1; +} + +static inline int encode_15_7_sl(Palette * palette, uint8_t * dest, + const uint8_t * src, int width, int dist) +{ + int len = 0, x; + for (x = 0; x < width; x++) { + len += write_pixel_15_7(palette, dest + len, src + 3 * x, dist); + } + return len; +} + +static int encode_15_7(Palette * palette, Block * b, const uint8_t * src, + int stride, int dist) +{ + int i; + uint8_t *ptr = b->enc; + for (i = 0; i < b->start; i++) + ptr += encode_15_7_sl(palette, ptr, src + i * stride, b->width, dist); + b->sl_begin = ptr; + for (; i < b->start + b->len; i++) + ptr += encode_15_7_sl(palette, ptr, src + i * stride, b->width, dist); + b->sl_end = ptr; + for (; i < b->height; i++) + ptr += encode_15_7_sl(palette, ptr, src + i * stride, b->width, dist); + b->enc_size = ptr - b->enc; + return b->enc_size; +} + +static int encode_block(FlashSV2Context *s, Palette * palette, Block * b, + Block * prev, const uint8_t * src, int stride, int comp, + int dist, int keyframe) +{ + unsigned buf_size = b->width * b->height * 6; + uint8_t *buf = s->blockbuffer; + int res; + + if (b->flags & COLORSPACE_15_7) { + encode_15_7(palette, b, src, stride, dist); + } else { + encode_bgr(b, src, stride); + } + + if (b->len > 0) { + b->data_size = buf_size; + res = encode_zlib(b, b->data, &b->data_size, comp); + if (res) + return res; + + if (!keyframe) { + res = encode_zlibprime(b, prev, buf, &buf_size, comp); + if (res) + return res; + + if (buf_size < b->data_size) { + b->data_size = buf_size; + memcpy(b->data, buf, buf_size); + b->flags |= ZLIB_PRIME_COMPRESS_PREVIOUS; + } + } + } else { + b->data_size = 0; + } + return 0; +} + +static int compare_sl(FlashSV2Context * s, Block * b, const uint8_t * src, + uint8_t * frame, uint8_t * key, int y, int keyframe) +{ + if (memcmp(src, frame, b->width * 3) != 0) { + b->dirty = 1; + memcpy(frame, src, b->width * 3); +#ifndef FLASHSV2_DUMB + s->diff_lines++; +#endif + } + if (memcmp(src, key, b->width * 3) != 0) { + if (b->len == 0) + b->start = y; + b->len = y + 1 - b->start; + } + return 0; +} + +static int mark_all_blocks(FlashSV2Context * s, const uint8_t * src, int stride, + int keyframe) +{ + int sl, rsl, col, pos, possl; + Block *b; + for (sl = s->image_height - 1; sl >= 0; sl--) { + for (col = 0; col < s->cols; col++) { + rsl = s->image_height - sl - 1; + b = s->frame_blocks + col + rsl / s->block_height * s->cols; + possl = stride * sl + col * s->block_width * 3; + pos = s->image_width * rsl * 3 + col * s->block_width * 3; + compare_sl(s, b, src + possl, s->current_frame + pos, + s->key_frame + pos, rsl % s->block_height, keyframe); + } + } +#ifndef FLASHSV2_DUMB + s->tot_lines += s->image_height * s->cols; +#endif + return 0; +} + +static int encode_all_blocks(FlashSV2Context * s, int keyframe) +{ + int row, col, res; + uint8_t *data; + Block *b, *prev; + for (row = 0; row < s->rows; row++) { + for (col = 0; col < s->cols; col++) { + b = s->frame_blocks + (row * s->cols + col); + prev = s->key_blocks + (row * s->cols + col); + b->flags = s->use15_7 ? COLORSPACE_15_7 : 0; + if (keyframe) { + b->start = 0; + b->len = b->height; + } else if (!b->dirty) { + b->start = 0; + b->len = 0; + b->data_size = 0; + continue; + } else if (b->start != 0 || b->len != b->height) { + b->flags |= HAS_DIFF_BLOCKS; + } + data = s->current_frame + s->image_width * 3 * s->block_height * row + s->block_width * col * 3; + res = encode_block(s, &s->palette, b, prev, data, s->image_width * 3, s->comp, s->dist, keyframe); +#ifndef FLASHSV2_DUMB + if (b->dirty) + s->diff_blocks++; + s->comp_size += b->data_size; + s->uncomp_size += b->enc_size; +#endif + if (res) + return res; + } + } +#ifndef FLASHSV2_DUMB + s->raw_size += s->image_width * s->image_height * 3; + s->tot_blocks += s->rows * s->cols; +#endif + return 0; +} + +static int write_all_blocks(FlashSV2Context * s, uint8_t * buf, + int buf_size) +{ + int row, col, buf_pos = 0, len; + Block *b; + for (row = 0; row < s->rows; row++) { + for (col = 0; col < s->cols; col++) { + b = s->frame_blocks + row * s->cols + col; + len = write_block(b, buf + buf_pos, buf_size - buf_pos); + b->start = b->len = b->dirty = 0; + if (len < 0) + return len; + buf_pos += len; + } + } + return buf_pos; +} + +static int write_bitstream(FlashSV2Context * s, const uint8_t * src, int stride, + uint8_t * buf, int buf_size, int keyframe) +{ + int buf_pos, res; + + res = mark_all_blocks(s, src, stride, keyframe); + if (res) + return res; + res = encode_all_blocks(s, keyframe); + if (res) + return res; + + res = write_header(s, buf, buf_size); + if (res < 0) { + return res; + } else { + buf_pos = res; + } + res = write_all_blocks(s, buf + buf_pos, buf_size - buf_pos); + if (res < 0) + return res; + buf_pos += res; +#ifndef FLASHSV2_DUMB + s->total_bits += ((double) buf_pos) * 8.0; +#endif + + return buf_pos; +} + +static void recommend_keyframe(FlashSV2Context * s, int *keyframe) +{ +#ifndef FLASHSV2_DUMB + double block_ratio, line_ratio, enc_ratio, comp_ratio, data_ratio; + if (s->avctx->gop_size > 0) { + block_ratio = s->diff_blocks / s->tot_blocks; + line_ratio = s->diff_lines / s->tot_lines; + enc_ratio = s->uncomp_size / s->raw_size; + comp_ratio = s->comp_size / s->uncomp_size; + data_ratio = s->comp_size / s->raw_size; + + if ((block_ratio >= 0.5 && line_ratio / block_ratio <= 0.5) || line_ratio >= 0.95) { + *keyframe = 1; + return; + } + } +#else + return; +#endif +} + +#ifndef FLASHSV2_DUMB +static const double block_size_fraction = 1.0 / 300; +static const double use15_7_threshold = 8192; +static const double color15_7_factor = 100; +#endif +static int optimum_block_width(FlashSV2Context * s) +{ +#ifndef FLASHSV2_DUMB + double save = (1-pow(s->diff_lines/s->diff_blocks/s->block_height, 0.5)) * s->comp_size/s->tot_blocks; + double width = block_size_fraction * sqrt(0.5 * save * s->rows * s->cols) * s->image_width; + int pwidth = ((int) width); + return FFCLIP(pwidth & ~15, 256, 16); +#else + return 64; +#endif +} + +static int optimum_block_height(FlashSV2Context * s) +{ +#ifndef FLASHSV2_DUMB + double save = (1-pow(s->diff_lines/s->diff_blocks/s->block_height, 0.5)) * s->comp_size/s->tot_blocks; + double height = block_size_fraction * sqrt(0.5 * save * s->rows * s->cols) * s->image_height; + int pheight = ((int) height); + return FFCLIP(pheight & ~15, 256, 16); +#else + return 64; +#endif +} + +static int optimum_use15_7(FlashSV2Context * s) +{ +#ifndef FLASHSV2_DUMB + double ideal = ((double)(s->avctx->bit_rate * s->avctx->time_base.den * s->avctx->ticks_per_frame)) / + ((double) s->avctx->time_base.num) * s->avctx->frame_number; + if (ideal + use15_7_threshold < s->total_bits) { + return 1; + } else { + return 0; + } +#else + return s->avctx->global_quality == 0; +#endif +} + +static int optimum_dist(FlashSV2Context * s) +{ +#ifndef FLASHSV2_DUMB + double ideal = + s->avctx->bit_rate * s->avctx->time_base.den * + s->avctx->ticks_per_frame; + int dist = pow((s->total_bits / ideal) * color15_7_factor, 3); + av_log(s->avctx, AV_LOG_DEBUG, "dist: %d\n", dist); + return dist; +#else + return 15; +#endif +} + + +static int reconfigure_at_keyframe(FlashSV2Context * s, const uint8_t * image, + int stride) +{ + int update_palette = 0; + int res; + int block_width = optimum_block_width (s); + int block_height = optimum_block_height(s); + + s->rows = (s->image_height + block_height - 1) / block_height; + s->cols = (s->image_width + block_width - 1) / block_width; + + if (block_width != s->block_width || block_height != s->block_height) { + s->block_width = block_width; + s->block_height = block_height; + if (s->rows * s->cols > s->blocks_size / sizeof(Block)) { + s->frame_blocks = av_realloc_array(s->frame_blocks, s->rows, s->cols * sizeof(Block)); + s->key_blocks = av_realloc_array(s->key_blocks, s->cols, s->rows * sizeof(Block)); + if (!s->frame_blocks || !s->key_blocks) { + av_log(s->avctx, AV_LOG_ERROR, "Memory allocation failed.\n"); + return -1; + } + s->blocks_size = s->rows * s->cols * sizeof(Block); + } + init_blocks(s, s->frame_blocks, s->encbuffer, s->databuffer); + init_blocks(s, s->key_blocks, s->keybuffer, 0); + + av_fast_malloc(&s->blockbuffer, &s->blockbuffer_size, block_width * block_height * 6); + if (!s->blockbuffer) { + av_log(s->avctx, AV_LOG_ERROR, "Could not allocate block buffer.\n"); + return AVERROR(ENOMEM); + } + } + + s->use15_7 = optimum_use15_7(s); + if (s->use15_7) { + if ((s->use_custom_palette && s->palette_type != 1) || update_palette) { + res = generate_optimum_palette(&s->palette, image, s->image_width, s->image_height, stride); + if (res) + return res; + s->palette_type = 1; + av_log(s->avctx, AV_LOG_DEBUG, "Generated optimum palette\n"); + } else if (!s->use_custom_palette && s->palette_type != 0) { + res = generate_default_palette(&s->palette); + if (res) + return res; + s->palette_type = 0; + av_log(s->avctx, AV_LOG_DEBUG, "Generated default palette\n"); + } + } + + + reset_stats(s); + + return 0; +} + +static int flashsv2_encode_frame(AVCodecContext *avctx, AVPacket *pkt, + const AVFrame *p, int *got_packet) +{ + FlashSV2Context *const s = avctx->priv_data; + int res; + int keyframe = 0; + + if ((res = ff_alloc_packet2(avctx, pkt, s->frame_size + FF_MIN_BUFFER_SIZE)) < 0) + return res; + + /* First frame needs to be a keyframe */ + if (avctx->frame_number == 0) + keyframe = 1; + + /* Check the placement of keyframes */ + if (avctx->gop_size > 0) { + if (avctx->frame_number >= s->last_key_frame + avctx->gop_size) + keyframe = 1; + } + + if (!keyframe + && avctx->frame_number > s->last_key_frame + avctx->keyint_min) { + recommend_keyframe(s, &keyframe); + if (keyframe) + av_log(avctx, AV_LOG_DEBUG, "Recommending key frame at frame %d\n", avctx->frame_number); + } + + if (keyframe) { + res = reconfigure_at_keyframe(s, p->data[0], p->linesize[0]); + if (res) + return res; + } + + if (s->use15_7) + s->dist = optimum_dist(s); + + res = write_bitstream(s, p->data[0], p->linesize[0], pkt->data, pkt->size, keyframe); + + if (keyframe) { + new_key_frame(s); + s->last_key_frame = avctx->frame_number; + pkt->flags |= AV_PKT_FLAG_KEY; + av_log(avctx, AV_LOG_DEBUG, "Inserting key frame at frame %d\n", avctx->frame_number); + } + + pkt->size = res; + *got_packet = 1; + + return 0; +} + +static av_cold int flashsv2_encode_end(AVCodecContext * avctx) +{ + FlashSV2Context *s = avctx->priv_data; + + cleanup(s); + + return 0; +} + +AVCodec ff_flashsv2_encoder = { + .name = "flashsv2", + .long_name = NULL_IF_CONFIG_SMALL("Flash Screen Video Version 2"), + .type = AVMEDIA_TYPE_VIDEO, + .id = AV_CODEC_ID_FLASHSV2, + .priv_data_size = sizeof(FlashSV2Context), + .init = flashsv2_encode_init, + .encode2 = flashsv2_encode_frame, + .close = flashsv2_encode_end, + .pix_fmts = (const enum AVPixelFormat[]){ AV_PIX_FMT_BGR24, AV_PIX_FMT_NONE }, +}; |
