/*
 * FLV to MPEG4 converter
 *
 * Copyright (c) 2006 vixy project
 *
 * This file contains the code that based on FFmpeg (http://ffmpeg.mplayerhq.hu/)
 * See original copyright notice in /FFMPEG_CREDITS and /FFMPEG_IMPORTS
 *
 * This file is part of VIXY FLV Converter.
 *
 * 'VIXY FLV Converter' 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.
 *
 * 'VIXY FLV Converter' 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
 */

#include "m4v.h"
#include "bitwriter.h"
#include "flv.h"
#include "m4vencode.h"
#include "../flv2mpeg4.h"

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////
typedef struct _CONVCTX
{
	int width;
	int height;

	int frame;
	int icounter;

	M4V_VOL vol;
} CONVCTX;


typedef struct
{
	uint8   *out_buf;
	M4V_VOL  vol;
	CONVCTX  conv;
} CTX;

#define VOL_TIME_BITS       5
#define PACKETBUFFER_SIZE   (256*1024*4)

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////
static const uint8 ff_mpeg4_y_dc_scale_table[32] =
{
//  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
	0, 8, 8, 8, 8, 10, 12, 14, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 34, 36, 38, 40, 42, 44, 46
};

static const uint8 ff_mpeg4_c_dc_scale_table[32] =
{
//  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
	0, 8, 8, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 14, 15, 15, 16, 16, 17, 17, 18, 18, 19, 20, 21, 22, 23, 24, 25
};


static void copy_vol(PICTURE *flv_pic, M4V_VOL *vol)
{
	vol->width = flv_pic->width;
	vol->height = flv_pic->height;
	vol->time_bits = VOL_TIME_BITS; // 0-31
}

static void copy_vop(PICTURE *flv_pic, M4V_VOP *vop, CONVCTX *c)
{
	vop->qscale = flv_pic->qscale;

	vop->time = c->frame % 30;
	vop->icount = (c->icounter + 29) / 30;
	vop->intra_dc_threshold = 99;

	if (flv_pic->picture_type == FLV_I_TYPE)
	{
		vop->picture_type = M4V_I_TYPE;
	}
	else
	{
		vop->picture_type = M4V_P_TYPE;
		vop->f_code = 1;
	}
}

static void copy_microblock(MICROBLOCK *flv_mb, M4V_MICROBLOCK *m4v_mb)
{
	int i;

	m4v_mb->dquant = flv_mb->dquant;
	memcpy(m4v_mb->block, flv_mb->block, sizeof(m4v_mb->block)); // !!!!!!!
	m4v_mb->intra = flv_mb->intra;
	m4v_mb->skip = flv_mb->skip;
	m4v_mb->mv_type = flv_mb->mv_type;

	memcpy(m4v_mb->mv_x, flv_mb->mv_x, sizeof(m4v_mb->mv_x)); // !!!!!!
	memcpy(m4v_mb->mv_y, flv_mb->mv_y, sizeof(m4v_mb->mv_y)); // !!!!!!

	// dc rescale
	if (m4v_mb->intra)
	{
		for (i = 0; i < 4; i++)
		{
			m4v_mb->block[i].block[0] *= 8;
			m4v_mb->block[i].block[0] /= ff_mpeg4_y_dc_scale_table[m4v_mb->qscale];
		}

		for (i = 4; i < 6; i++)
		{
			m4v_mb->block[i].block[0] *= 8;
			m4v_mb->block[i].block[0] /= ff_mpeg4_c_dc_scale_table[m4v_mb->qscale];
		}
	}
}

static int write_pad_not_coded_frames(flv2mpeg4_CTX *pub_ctx, CONVCTX *c, BW *bw, uint32 time)
{
	// if any timecode padding is needed, then pad.
	while (c->frame * 1000 / 30 < time)
	{
		M4V_VOP vop;
		memset(&vop, 0, sizeof(vop));
		vop.picture_type = M4V_P_TYPE;
		vop.time = c->frame % 30;
		vop.icount = (c->icounter + 29) / 30;
		m4v_encode_vop_header(bw, &vop, VOL_TIME_BITS, 1);
		m4v_stuffing(bw);

		flash_bw(bw);

		// write frame
		if (pub_ctx->write_packet_cb(pub_ctx->usr_data,
		        0,
		        0,//c->frame,
		        bw->buf,
		        bw->pos) < 0)
		{
			return -1;
		}

		clear_bw(bw);

		c->frame++;
		c->icounter++;
	}

	return 0;
}

static int write_m4v_picture_frame(flv2mpeg4_CTX *pub_ctx, CONVCTX *c, BR *br, BW *bw, PICTURE *flvpic, uint32 time)
{
	MICROBLOCK mb;
	M4V_VOP vop;
	M4V_MICROBLOCK m4v_mb;
	int x, y;
	int mb_width = (flvpic->width + 15) / 16;
	int mb_height = (flvpic->height + 15) / 16;

	memset(&vop, 0, sizeof(vop));

	copy_vop(flvpic, &vop, c);
	m4v_encode_vop_header(bw, &vop, VOL_TIME_BITS, 0);

	// transcode flv to mpeg4
	for (y = 0; y < mb_height; y++)
	{
		for (x = 0; x < mb_width; x++)
		{
			memset(&mb, 0, sizeof(mb));
			memset(&m4v_mb, 0, sizeof(m4v_mb));

			if (vop.picture_type == M4V_I_TYPE)
			{
				mb.intra = 1;
				if (decode_I_mb(br, &mb, flvpic->escape_type, flvpic->qscale) < 0) return -1;
				m4v_mb.qscale = vop.qscale;
				copy_microblock(&mb, &m4v_mb);
				m4v_encode_I_dcpred(&m4v_mb, &c->vol.dcpred, x, y);
				m4v_encode_I_mb(bw, &m4v_mb);
			}
			else
			{
				if (decode_P_mb(br, &mb, flvpic->escape_type, flvpic->qscale) < 0) return -1;
				m4v_mb.qscale = vop.qscale;
				copy_microblock(&mb, &m4v_mb);
				m4v_encode_I_dcpred(&m4v_mb, &c->vol.dcpred, x, y);
				m4v_encode_P_mb(bw, &m4v_mb);
			}
		}
	}

	m4v_stuffing(bw);
	flash_bw(bw);

	// write frame
	if (pub_ctx->write_packet_cb(pub_ctx->usr_data,
	        vop.picture_type == M4V_I_TYPE,
	        0,//c->frame,
	        bw->buf,
	        bw->pos) < 0)
	{
		return -1;
	}

	c->frame++;
	c->icounter++;

	return 0;
}

static int write_m4v_frame(flv2mpeg4_CTX *pub_ctx, CONVCTX *c, BR *br, BW *bw, uint32 time)
{
	PICTURE picture;

	memset(&picture, 0, sizeof(picture));
	init_dcpred(&c->vol.dcpred);

	if (decode_picture_header(br, &picture) < 0) return -1;
	if (c->width != picture.width || c->height != picture.height) return -1; //size changed..

	copy_vol(&picture, &c->vol);

	if (picture.picture_type == FLV_I_TYPE)
	{
		c->icounter = 0;
	}
	else
	{
		if (write_pad_not_coded_frames(pub_ctx, c, bw, time) < 0) return -1;
	}

	if (write_m4v_picture_frame(pub_ctx, c, br, bw, &picture, time) < 0)
	{
		return -1;
	}

	return 0;
}

int flv2mpeg4_process_flv_packet(flv2mpeg4_CTX *ctx, uint8 picture_type, const uint8 *buf, uint32 size, uint32 time)
{
	CTX *p = ctx->priv;
	BR br;
	BW bw;
	init_br(&br, buf, size);
	init_bw(&bw, p->out_buf, PACKETBUFFER_SIZE);
	write_m4v_frame(ctx, &p->conv, &br, &bw, time);
	return 0;
}

int flv2mpeg4_prepare_extra_data(flv2mpeg4_CTX *ctx)
{
	CTX *p = ctx->priv;
	BW bw;
	CONVCTX *c = &(p->conv);

	M4V_VOP vop;
	memset(&vop, 0, sizeof(vop));

	init_bw(&bw, p->out_buf, PACKETBUFFER_SIZE);

	c->vol.width = c->width;
	c->vol.height = c->height;
	c->vol.time_bits = VOL_TIME_BITS; // 0-31

	m4v_encode_m4v_header(&bw, &c->vol, 0);

	m4v_stuffing(&bw);
	flash_bw(&bw);

	alloc_dcpred(&c->vol.dcpred, (c->width + 15) / 16, (c->height + 15) / 16);

	return ctx->write_extradata_cb(ctx->usr_data, c->width, c->height, 200 * 1000, bw.buf, bw.pos);
}

void flv2mpeg4_set_frame(flv2mpeg4_CTX *ctx, int frame, int icounter)
{
	CTX *p = ctx->priv;
	p->conv.frame = frame;
	p->conv.icounter = icounter;
}

flv2mpeg4_CTX *flv2mpeg4_init_ctx(void *priv_data, int width, int height, flv2mpeg4_write_packet_cb wp_cb, flv2mpeg4_write_extradata_cb we_cb)
{
	flv2mpeg4_CTX *pub_ctx = malloc(sizeof(flv2mpeg4_CTX));
	memset(pub_ctx, 0x0, sizeof(flv2mpeg4_CTX));
	pub_ctx->usr_data = priv_data;
	pub_ctx->write_packet_cb = wp_cb;
	pub_ctx->write_extradata_cb = we_cb;
	pub_ctx->priv = malloc(sizeof(CTX));
	memset(pub_ctx->priv, 0x0, sizeof(CTX));
	CTX *ctx = pub_ctx->priv;

	ctx->conv.width  = width;
	ctx->conv.height = height;
	ctx->out_buf = malloc(PACKETBUFFER_SIZE);
	memset(ctx->out_buf, 0x0, PACKETBUFFER_SIZE);
	memset(&(ctx->vol), 0x0, sizeof(ctx->vol));

	return pub_ctx;
}

void flv2mpeg4_release_ctx(flv2mpeg4_CTX **pub_ctx)
{
	CTX *ctx = (*pub_ctx)->priv;

	free_dcpred(&ctx->conv.vol.dcpred);
	free(ctx->out_buf);
	free(ctx);
	free(*pub_ctx);
	*pub_ctx = NULL;
}