[FFmpeg-devel] [PATCH] encoder for adobe's flash ScreenVideo2
Leon Ou
leono
Wed Mar 16 06:53:10 CET 2011
Hi all,
In the mail list, I find a encoder for adobe's flash ScreenVideo2 written by Joshua. After read the code below. I make some changes to this code to decreases the size of encoded data for the situation of pool bandwidth.
In Joshua code, the low 3 bits of every channel of RGB are discarded. But in my code, the low 4 bits of every channel of RGB are discarded. After the test, discarding the low 4 bits doesn't lower the picture quality significantly.
Below is the test data of this two ways:
A Screen capture with 1440*900, the raw data is 3.7MB.
Reserving high 5 bits +Default Palette+ZLIB..................The encode size is 680KB
Reserving high 4 bits +Default Palette+ZLIB..................The encode size is 350KB
After discussion with Joshua, I change one method in his code and add two new methods to compatible the two ways.
1.Change the method: pixel_color15.
static inline unsigned pixel_color15(const uint8_t * src, int mask)
{
return ((src[0] & mask) >> 3) | ((src[1] & mask) << 2) | ((src[2] & mask) << 7);
}
Add a parameter 'mask' to the pixel_color15
2. Add two new methods.
static int update_palette_index_size(Palette * palette)
{
for(int i =0; i<32768;i++)
{
palette->index[i] = 0x80;
}
for (int index = 0; index < 128; index++)
{
uint8_t c_r = palette->colors[index]>>16;
uint8_t c_g = palette->colors[index]>>8 & 0xff;
uint8_t c_b = palette->colors[index] & 0xff;
unsigned palette_color_15 = ((c_b & 0xf0) >> 3) | ((c_g & 0xf0) << 2) | ((c_r & 0xf0) << 7);
unsigned short bgri = (unsigned short)palette_color_15;
palette->index[bgri] = index;
}
return 0;
}
static int write_pixel_15_7_size(Palette * palette, uint8_t * dest, const uint8_t * src, int dist)
{
unsigned short c15_4bits = pixel_color15(src, mask);
if (palette->index[c15_4bits]!=0x80)
{
dest[0] = (uint8_t) palette->index[c15_4bits];
return 1;
}
else
{
dest[0] = 0x80 | (uint8_t) (c15_4bits >> 8);
dest[1] = c15_4bits & 0xff;
return 2;
}
}
Whiling focus on screen capture image size, the update_palette_index_size and write_pixel_15_7_size will be replace the update_palette_index and write_pixel_15_7 in your code. In the write_pixel_15_7_size, the 'dist' parameter is used as 'mask'. So, in the flashsv2_encode_frame, the dist should be set to 0xF0.
Whiling focus on screen capture image quality, the update_palette_index and write_pixel_15_7 should be chosen and passes the "0xF1" for the 'mask' parameter of method pixel_color15.
Him
I fixed the issues you guys have commented on (tell me if I
accidentally missed one), and the revised patch is attached.
Joshua Warner
On Wed, Jul 22, 2009 at 10:40 AM, Vitor Sessak<vitor1001 at gmail.com<https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel>> wrote:
> Joshua Warner wrote:
>>
>> On Tue, Jul 21, 2009 at 12:13 PM, Daniel Verkamp<daniel at drv.nu<https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel>> wrote:
>>>
>>> On Tue, Jul 21, 2009 at 10:57 AM, Joshua Warner<joshuawarner32 at gmail.com<https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel>>
>>> wrote:
>>>>
>>>> Hi all,
>>>>
>>>> I've developed an encoder for Adobe's Flash ScreenVideo2 format, which
>>>> is
>>>> stored in flv files. My encoder currently only supports a large subset
>>>> of
>>>> the format. The only player that supports this codec (so far) is Adobe
>>>> Flash Player itself, but ScreenVideo2 makes dramatic improvement in file
>>>> size over ScreenVideo (currently in ffmpeg as flashsv) - and should be
>>>> very
>>>> useful for uploading screencasts, etc. Most options (block size, etc)
>>>> now
>>>> just fall back on defaults because I couldn't find a general algorithm
>>>> that
>>>> produced consistantly better results than these. All the code is in
>>>> place
>>>> to be able to change these parameters dynamically, so future
>>>> improvements
>>>> there should be easy. The patch is attached.
>>>>
>>>> The codec is listed as flashsv2 in ffmpeg.
>>>>
>>>> Joshua Warner
>>>
>>> Minor nitpicks:
>>> - "palette" is misspelled as "pallet" throughout
>>> - trailing whitespace on 2 lines
>>> - plenty of warnings from tools/patcheck
>>
>> I ran tools/patcheck (which I wasn't aware of before), and most of the
>> output was either false positives or would reduce readability of the
>> code.
>
> It does gives a few false positives. All the "x==0 / x!=0 can be simplified
> to !x / x" is a matter of preferred style in FFmpeg (the readability depends
> on how used you are to it). The "missing const" are mostly correct.
>
>> I'm not sure what to do about the comments that it complains
>> are not doxygen compliant - they are things that don't have any
>> applicability outside flashsv2enc.c... should I appease patcheck?
>
> We prefer to add doxy comments for things that would improve the doxygen
> documentation of the file. Typically struct members and comments before
> functions describing what it does.
>
> -Vitor
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at mplayerhq.hu<https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel>
> https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel
>
-------------- next part --------------
Index: configure
===================================================================
--- configure (revision 19479)
+++ configure (working copy)
@@ -1065,6 +1065,7 @@
flac_encoder_select="golomb"
flashsv_decoder_select="zlib"
flashsv_encoder_select="zlib"
+flashsv2_encoder_select="zlib"
flv_encoder_select="aandct"
h261_encoder_select="aandct"
h263_encoder_select="aandct"
Index: Changelog
===================================================================
--- Changelog (revision 19479)
+++ Changelog (working copy)
@@ -191,6 +191,7 @@
- Gopher client support
- MXF D-10 muxer
- generic metadata API
+- flash ScreenVideo2 encoder
Index: libavcodec/allcodecs.c
===================================================================
--- libavcodec/allcodecs.c (revision 19479)
+++ libavcodec/allcodecs.c (working copy)
@@ -92,6 +92,7 @@
REGISTER_ENCDEC (FFV1, ffv1);
REGISTER_ENCDEC (FFVHUFF, ffvhuff);
REGISTER_ENCDEC (FLASHSV, flashsv);
+ REGISTER_ENCODER (FLASHSV2, flashsv2);
REGISTER_DECODER (FLIC, flic);
REGISTER_ENCDEC (FLV, flv);
REGISTER_DECODER (FOURXM, fourxm);
Index: libavcodec/avcodec.h
===================================================================
--- libavcodec/avcodec.h (revision 19479)
+++ libavcodec/avcodec.h (working copy)
@@ -30,7 +30,7 @@
#include "libavutil/avutil.h"
#define LIBAVCODEC_VERSION_MAJOR 52
-#define LIBAVCODEC_VERSION_MINOR 32
+#define LIBAVCODEC_VERSION_MINOR 33
#define LIBAVCODEC_VERSION_MICRO 0
#define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
@@ -198,6 +198,7 @@
CODEC_ID_V210,
CODEC_ID_DPX,
CODEC_ID_MAD,
+ CODEC_ID_FLASHSV2,
/* various PCM "codecs" */
CODEC_ID_PCM_S16LE= 0x10000,
Index: libavcodec/Makefile
===================================================================
--- libavcodec/Makefile (revision 19479)
+++ libavcodec/Makefile (working copy)
@@ -92,6 +92,7 @@
OBJS-$(CONFIG_FLAC_ENCODER) += flacenc.o flacdata.o flac.o lpc.o
OBJS-$(CONFIG_FLASHSV_DECODER) += flashsv.o
OBJS-$(CONFIG_FLASHSV_ENCODER) += flashsvenc.o
+OBJS-$(CONFIG_FLASHSV2_ENCODER) += flashsv2enc.o
OBJS-$(CONFIG_FLIC_DECODER) += flicvideo.o
OBJS-$(CONFIG_FLV_DECODER) += h263dec.o h263.o mpeg12data.o mpegvideo.o error_resilience.o
OBJS-$(CONFIG_FLV_ENCODER) += mpegvideo_enc.o motion_est.o ratecontrol.o h263.o mpeg12data.o mpegvideo.o error_resilience.o
Index: libavcodec/flashsv2enc.c
===================================================================
--- libavcodec/flashsv2enc.c (revision 0)
+++ libavcodec/flashsv2enc.c (revision 0)
@@ -0,0 +1,912 @@
+/*
+ * 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 libavcodec/flashsv2enc.c
+ * 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 "avcodec.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;
+ AVFrame frame;
+ uint8_t *encbuffer;
+ uint8_t *keybuffer;
+ uint8_t *databuffer;
+
+ 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)
+{
+ if (s->encbuffer)
+ av_free(s->encbuffer);
+ if (s->keybuffer)
+ av_free(s->keybuffer);
+ if (s->databuffer)
+ av_free(s->databuffer);
+ if (s->current_frame)
+ av_free(s->current_frame);
+ if (s->key_frame)
+ av_free(s->key_frame);
+
+ if (s->frame_blocks)
+ av_free(s->frame_blocks);
+ if (s->key_blocks)
+ av_free(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 4096x4096 !\n");
+ return -1;
+ }
+
+ if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 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;
+
+ 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);
+
+ 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;
+ FFSWAP(uint8_t * , s->keybuffer, s->encbuffer);
+ 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;
+ }
+
+ 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 * 8);
+
+ 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++] = (uint8_t) (b->start);
+ buf[buf_pos++] = (uint8_t) (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++] = (uint8_t) (b->col);
+ buf[buf_pos++] = (uint8_t) (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] = (uint8_t) c7;
+ return 1;
+ } else {
+ dest[0] = 0x80 | (uint8_t) (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(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[buf_size];
+ 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);
+ if (keyframe) {
+ b->start = 0;
+ b->len = b->height;
+ b->flags = s->use15_7 ? COLORSPACE_15_7 : 0;
+ } else if (!b->dirty) {
+ b->start = 0;
+ b->len = 0;
+ b->data_size = 0;
+ b->flags = s->use15_7 ? COLORSPACE_15_7 : 0;
+ continue;
+ } else {
+ b->flags = s->use15_7 ? COLORSPACE_15_7 | HAS_DIFF_BLOCKS : HAS_DIFF_BLOCKS;
+ }
+ data = s->current_frame + s->image_width * 3 * s->block_height * row + s->block_width * col * 3;
+ res = encode_block(&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
+}
+
+static const double block_size_fraction = 1.0 / 300;
+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 const double use15_7_threshold = 8192;
+
+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 const double color15_7_factor = 100;
+
+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;
+ s->block_width = optimum_block_width(s);
+ s->block_height = optimum_block_height(s);
+
+ s->rows = (s->image_height + s->block_height - 1) / s->block_height;
+ s->cols = (s->image_width + s->block_width - 1) / s->block_width;
+
+ if (s->rows * s->cols != s->blocks_size / sizeof(Block)) {
+ if (s->rows * s->cols > s->blocks_size / sizeof(Block)) {
+ s->frame_blocks = av_realloc(s->frame_blocks, s->rows * s->cols * sizeof(Block));
+ s->key_blocks = av_realloc(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);
+
+ }
+
+ 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, uint8_t * buf,
+ int buf_size, void *data)
+{
+ FlashSV2Context *const s = avctx->priv_data;
+ AVFrame *pict = data;
+ AVFrame *const p = &s->frame;
+ int res;
+ int keyframe = 0;
+
+ *p = *pict;
+
+ /* 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 (buf_size < s->frame_size) {
+ //Conservative upper bound check for compressed data
+ av_log(avctx, AV_LOG_ERROR, "buf_size %d < %d\n", buf_size, s->frame_size);
+ return -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], buf, buf_size, keyframe);
+
+ if (keyframe) {
+ new_key_frame(s);
+ p->pict_type = FF_I_TYPE;
+ p->key_frame = 1;
+ s->last_key_frame = avctx->frame_number;
+ av_log(avctx, AV_LOG_DEBUG, "Inserting key frame at frame %d\n", avctx->frame_number);
+ } else {
+ p->pict_type = FF_P_TYPE;
+ p->key_frame = 0;
+ }
+
+ avctx->coded_frame = p;
+
+ return res;
+}
+
+static av_cold int flashsv2_encode_end(AVCodecContext * avctx)
+{
+ FlashSV2Context *s = avctx->priv_data;
+
+ cleanup(s);
+
+ return 0;
+}
+
+AVCodec flashsv2_encoder = {
+ "flashsv2",
+ CODEC_TYPE_VIDEO,
+ CODEC_ID_FLASHSV2,
+ sizeof(FlashSV2Context),
+ flashsv2_encode_init,
+ flashsv2_encode_frame,
+ flashsv2_encode_end,
+ .pix_fmts = (enum PixelFormat[]) {PIX_FMT_BGR24, PIX_FMT_NONE},
+ .long_name = NULL_IF_CONFIG_SMALL("Flash Screen Video Version 2"),
+};
Index: doc/general.texi
===================================================================
--- doc/general.texi (revision 19479)
+++ doc/general.texi (working copy)
@@ -350,6 +350,7 @@
@tab experimental lossless codec (fourcc: FFV1)
@item Flash Screen Video v1 @tab X @tab X
@tab fourcc: FSV1
+ at item<https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel> Flash Screen Video v2 @tab X
@item Flash Video (FLV) @tab X @tab X
@tab Sorenson H.263 used in Flash
@item Fraps @tab @tab X
Index: libavformat/flvenc.c
===================================================================
--- libavformat/flvenc.c (revision 19479)
+++ libavformat/flvenc.c (working copy)
@@ -29,6 +29,7 @@
static const AVCodecTag flv_video_codec_ids[] = {
{CODEC_ID_FLV1, FLV_CODECID_H263 },
{CODEC_ID_FLASHSV, FLV_CODECID_SCREEN},
+ {CODEC_ID_FLASHSV2, FLV_CODECID_SCREEN2},
{CODEC_ID_VP6F, FLV_CODECID_VP6 },
{CODEC_ID_VP6, FLV_CODECID_VP6 },
{CODEC_ID_H264, FLV_CODECID_H264 },
Regards,
Leon
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