Avoid passing test invalid arguments when string is empty.

[mplayer/glamo.git] / libmpcodecs / vf_zrmjpeg.c

/**
 * \file vf_zrmjpeg.c
 *
 * \brief Does mjpeg encoding as required by the zrmjpeg filter as well
 * as by the zr video driver.
 */
/*
 * Copyright (C) 2005 Rik Snel <rsnel@cube.dyndns.org>, license GPL v2
 * - based on vd_lavc.c by A'rpi (C) 2002-2003
 * - parts from ffmpeg Copyright (c) 2000-2003 Fabrice Bellard
 *
 * This files includes a straightforward (to be) optimized JPEG encoder for
 * the YUV422 format, based on mjpeg code from ffmpeg.
 *
 * For an excellent introduction to the JPEG format, see:
 * http://www.ece.purdue.edu/~bouman/grad-labs/lab8/pdf/lab.pdf
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <inttypes.h>

#include "config.h"
#include "mp_msg.h"

#include "img_format.h"
#include "mp_image.h"
#include "vf.h"

#ifdef USE_FASTMEMCPY
#include "libvo/fastmemcpy.h"
#endif

/* We need this #define because we need ../libavcodec/common.h to #define
 * be2me_32, otherwise the linker will complain that it doesn't exist */
#define HAVE_AV_CONFIG_H
#include "libavcodec/avcodec.h"
#include "libavcodec/dsputil.h"
#include "libavcodec/mpegvideo.h"
//#include "jpeg_enc.h" /* this file is not present yet */

#undef malloc
#undef free
#undef realloc

extern int avcodec_inited;

/* some convenient #define's, is this portable enough? */
/// Printout  with vf_zrmjpeg: prefix at VERBOSE level
#define VERBOSE(...) mp_msg(MSGT_DECVIDEO, MSGL_V, "vf_zrmjpeg: " __VA_ARGS__)
/// Printout with vf_zrmjpeg: prefix at ERROR level
#define ERROR(...) mp_msg(MSGT_DECVIDEO, MSGL_ERR, "vf_zrmjpeg: " __VA_ARGS__)
/// Printout with vf_zrmjpeg: prefix at WARNING level
#define WARNING(...) mp_msg(MSGT_DECVIDEO, MSGL_WARN, \
                "vf_zrmjpeg: " __VA_ARGS__)

// "local" flag in vd_ffmpeg.c. If not set, avcodec_init() et. al. need to be called
// set when init is done, so that initialization is not done twice.
extern int avcodec_inited;

/// structure copied from mjpeg.c
/* zrmjpeg_encode_mb needs access to these tables for the black & white
 * option */
typedef struct MJpegContext {
        uint8_t huff_size_dc_luminance[12];
        uint16_t huff_code_dc_luminance[12];
        uint8_t huff_size_dc_chrominance[12];
        uint16_t huff_code_dc_chrominance[12];

        uint8_t huff_size_ac_luminance[256];
        uint16_t huff_code_ac_luminance[256];
        uint8_t huff_size_ac_chrominance[256];
        uint16_t huff_code_ac_chrominance[256];
} MJpegContext;

/// The get_pixels() routine to use. The real routine comes from dsputil
static void (*get_pixels)(DCTELEM *restrict block, const uint8_t *pixels, int line_size);

/* Begin excessive code duplication ************************************/
/* Code coming from mpegvideo.c and mjpeg.c in ../libavcodec ***********/

/// copy of the table in mpegvideo.c
static const unsigned short aanscales[64] = {
        /**< precomputed values scaled up by 14 bits */
        16384, 22725, 21407, 19266, 16384, 12873,  8867,  4520,
        22725, 31521, 29692, 26722, 22725, 17855, 12299,  6270,
        21407, 29692, 27969, 25172, 21407, 16819, 11585,  5906,
        19266, 26722, 25172, 22654, 19266, 15137, 10426,  5315,
        16384, 22725, 21407, 19266, 16384, 12873,  8867,  4520,
        12873, 17855, 16819, 15137, 12873, 10114,  6967,  3552,
        8867,  12299, 11585, 10426,  8867,  6967,  4799,  2446,
        4520,   6270,  5906,  5315,  4520,  3552,  2446,  1247
};

/// Precompute DCT quantizing matrix
/**
 * This routine will precompute the combined DCT matrix with qscale
 * and DCT renorm needed by the MPEG encoder here. It is basically the
 * same as the routine with the same name in mpegvideo.c, except for
 * some coefficient changes. The matrix will be computed in two variations,
 * depending on the DCT version used. The second used by the MMX version of DCT.
 *
 * \param s MpegEncContext pointer
 * \param qmat[OUT] pointer to where the matrix is stored
 * \param qmat16[OUT] pointer to where matrix for MMX is stored.
 *                This matrix is not permutated
 *                and second 64 entries are bias
 * \param quant_matrix[IN] the quantizion matrix to use
 * \param bias bias for the quantizer
 * \param qmin minimum qscale value to set up for
 * \param qmax maximum qscale value to set up for
 *
 * Only rows between qmin and qmax will be populated in the matrix.
 * In this MJPEG encoder, only the value 8 for qscale is used.
 */
static void convert_matrix(MpegEncContext *s, int (*qmat)[64],
                uint16_t (*qmat16)[2][64], const uint16_t *quant_matrix,
                int bias, int qmin, int qmax) {
        int qscale;

        for(qscale = qmin; qscale <= qmax; qscale++) {
                int i;
                if (s->dsp.fdct == ff_jpeg_fdct_islow) {
                        for (i = 0; i < 64; i++) {
                                const int j = s->dsp.idct_permutation[i];
/* 16 <= qscale * quant_matrix[i] <= 7905
 * 19952         <= aanscales[i] * qscale * quant_matrix[i]      <= 249205026
 * (1<<36)/19952 >= (1<<36)/(aanscales[i] * qscale * quant_matrix[i])
 *                                                       >= (1<<36)/249205026
 * 3444240       >= (1<<36)/(aanscales[i] * qscale * quant_matrix[i])  >= 275 */
                                qmat[qscale][i] = (int)((UINT64_C(1) <<
                                        (QMAT_SHIFT-3))/
                                        (qscale*quant_matrix[j]));
                        }
                } else if (s->dsp.fdct == fdct_ifast) {
                        for (i = 0; i < 64; i++) {
                                const int j = s->dsp.idct_permutation[i];
/* 16 <= qscale * quant_matrix[i] <= 7905
 * 19952         <= aanscales[i] * qscale * quant_matrix[i]      <= 249205026
 * (1<<36)/19952 >= (1<<36)/(aanscales[i] * qscale * quant_matrix[i])
 *                                                       >= (1<<36)/249205026
 * 3444240       >= (1<<36)/(aanscales[i] * qscale * quant_matrix[i])  >= 275 */
                                qmat[qscale][i] = (int)((UINT64_C(1) <<
                                        (QMAT_SHIFT + 11))/(aanscales[i]
                                        *qscale * quant_matrix[j]));
                        }
                } else {
                        for (i = 0; i < 64; i++) {
                                const int j = s->dsp.idct_permutation[i];
/* We can safely assume that 16 <= quant_matrix[i] <= 255
 * So 16           <= qscale * quant_matrix[i]             <= 7905
 * so (1<<19) / 16 >= (1<<19) / (qscale * quant_matrix[i]) >= (1<<19) / 7905
 * so 32768        >= (1<<19) / (qscale * quant_matrix[i]) >= 67 */
                                qmat[qscale][i] = (int)((UINT64_C(1) <<
                                                QMAT_SHIFT_MMX) / (qscale
                                                        *quant_matrix[j]));
                                qmat16[qscale][0][i] = (1 << QMAT_SHIFT_MMX)
                                                /(qscale * quant_matrix[j]);

                                if (qmat16[qscale][0][i] == 0 ||
                                                qmat16[qscale][0][i] == 128*256)
                                        qmat16[qscale][0][i]=128*256-1;
                                qmat16[qscale][1][i]=ROUNDED_DIV(bias
                                                <<(16-QUANT_BIAS_SHIFT),
                                                qmat16[qscale][0][i]);
                        }
                }
        }
}

/// Emit the DC value into a MJPEG code sream
/**
 * This routine is only intended to be used from encode_block
 *
 * \param s pointer to MpegEncContext structure
 * \param val the DC value to emit
 * \param huff_size pointer to huffman code size array
 * \param huff_code pointer to the code array corresponding to \a huff_size
 *
 * This routine is a clone of mjpeg_encode_dc
 */
static inline void encode_dc(MpegEncContext *s, int val,
                uint8_t *huff_size, uint16_t *huff_code) {
        int mant, nbits;

        if (val == 0) {
                put_bits(&s->pb, huff_size[0], huff_code[0]);
        } else {
                mant = val;
                if (val < 0) {
                        val = -val;
                        mant--;
                }
                nbits= av_log2_16bit(val) + 1;
                put_bits(&s->pb, huff_size[nbits], huff_code[nbits]);
                put_bits(&s->pb, nbits, mant & ((1 << nbits) - 1));
        }
}

/// Huffman encode and emit one DCT block into the MJPEG code stream
/**
 * \param s pointer to MpegEncContext structure
 * \param block pointer to the DCT block to emit
 * \param n
 *
 * This routine is a duplicate of encode_block in mjpeg.c
 */
static void encode_block(MpegEncContext *s, DCTELEM *block, int n) {
        int mant, nbits, code, i, j;
        int component, dc, run, last_index, val;
        MJpegContext *m = s->mjpeg_ctx;
        uint8_t *huff_size_ac;
        uint16_t *huff_code_ac;

        /* DC coef */
        component = (n <= 3 ? 0 : n - 4 + 1);
        dc = block[0]; /* overflow is impossible */
        val = dc - s->last_dc[component];
        if (n < 4) {
                encode_dc(s, val, m->huff_size_dc_luminance,
                                m->huff_code_dc_luminance);
                huff_size_ac = m->huff_size_ac_luminance;
                huff_code_ac = m->huff_code_ac_luminance;
        } else {
                encode_dc(s, val, m->huff_size_dc_chrominance,
                                m->huff_code_dc_chrominance);
                huff_size_ac = m->huff_size_ac_chrominance;
                huff_code_ac = m->huff_code_ac_chrominance;
        }
        s->last_dc[component] = dc;

        /* AC coefs */

        run = 0;
        last_index = s->block_last_index[n];
        for (i = 1; i <= last_index; i++) {
                j = s->intra_scantable.permutated[i];
                val = block[j];
                if (val == 0) run++;
                else {
                        while (run >= 16) {
                                put_bits(&s->pb, huff_size_ac[0xf0],
                                                huff_code_ac[0xf0]);
                                run -= 16;
                        }
                        mant = val;
                        if (val < 0) {
                                val = -val;
                                mant--;
                        }

                        nbits= av_log2_16bit(val) + 1;
                        code = (run << 4) | nbits;

                        put_bits(&s->pb, huff_size_ac[code],
                                        huff_code_ac[code]);
                        put_bits(&s->pb, nbits, mant & ((1 << nbits) - 1));
                        run = 0;
                }
        }

        /* output EOB only if not already 64 values */
        if (last_index < 63 || run != 0)
                put_bits(&s->pb, huff_size_ac[0], huff_code_ac[0]);
}

/// clip overflowing DCT coefficients
/**
 * If the computed DCT coefficients in a block overflow, this routine
 * will go through them and clip them to be in the valid range.
 *
 * \param s pointer to MpegEncContext
 * \param block pointer to DCT block to process
 * \param last_index index of the last non-zero coefficient in block
 *
 * The max and min level, which are clipped to, are stored in
 * s->min_qcoeff and s->max_qcoeff respectively.
 */
static inline void clip_coeffs(MpegEncContext *s, DCTELEM *block,
                int last_index) {
        int i;
        const int maxlevel= s->max_qcoeff;
        const int minlevel= s->min_qcoeff;

        for (i = 0; i <= last_index; i++) {
                const int j = s->intra_scantable.permutated[i];
                int level = block[j];

                if (level > maxlevel) level=maxlevel;
                else if(level < minlevel) level=minlevel;
                block[j]= level;
        }
}

/* End excessive code duplication **************************************/

typedef struct {
        struct MpegEncContext *s;
        int cheap_upsample;
        int bw;
        int y_rs;
        int u_rs;
        int v_rs;
} jpeg_enc_t;

// Huffman encode and emit one MCU of MJPEG code
/**
 * \param j pointer to jpeg_enc_t structure
 *
 * This function huffman encodes one MCU, and emits the
 * resulting bitstream into the MJPEG code that is currently worked on.
 *
 * this function is a reproduction of the one in mjpeg, it includes two
 * changes, it allows for black&white encoding (it skips the U and V
 * macroblocks and it outputs the huffman code for 'no change' (dc) and
 * 'all zero' (ac)) and it takes 4 macroblocks (422) instead of 6 (420)
 */
static av_always_inline void zr_mjpeg_encode_mb(jpeg_enc_t *j) {

        MJpegContext *m = j->s->mjpeg_ctx;

        encode_block(j->s, j->s->block[0], 0);
        encode_block(j->s, j->s->block[1], 1);
        if (j->bw) {
                /* U */
                put_bits(&j->s->pb, m->huff_size_dc_chrominance[0],
                                m->huff_code_dc_chrominance[0]);
                put_bits(&j->s->pb, m->huff_size_ac_chrominance[0],
                                m->huff_code_ac_chrominance[0]);
                /* V */
                put_bits(&j->s->pb, m->huff_size_dc_chrominance[0],
                                m->huff_code_dc_chrominance[0]);
                put_bits(&j->s->pb, m->huff_size_ac_chrominance[0],
                                m->huff_code_ac_chrominance[0]);
        } else {
                /* we trick encode_block here so that it uses
                 * chrominance huffman tables instead of luminance ones
                 * (see the effect of second argument of encode_block) */
                encode_block(j->s, j->s->block[2], 4);
                encode_block(j->s, j->s->block[3], 5);
        }
}

/// Fill one DCT MCU from planar storage
/**
 * This routine will convert one MCU from YUYV planar storage into 4
 * DCT macro blocks, converting from 8-bit format in the planar
 * storage to 16-bit format used in the DCT.
 *
 * \param j pointer to jpeg_enc structure, and also storage for DCT macro blocks
 * \param x pixel x-coordinate for the first pixel
 * \param y pixel y-coordinate for the first pixel
 * \param y_data pointer to the Y plane
 * \param u_data pointer to the U plane
 * \param v_data pointer to the V plane
 */
static av_always_inline void fill_block(jpeg_enc_t *j, int x, int y,
                unsigned char *y_data, unsigned char *u_data,
                unsigned char *v_data)
{
        int i, k;
        short int *dest;
        unsigned char *source;

        // The first Y, Y0
        get_pixels(j->s->block[0], y*8*j->y_rs + 16*x + y_data, j->y_rs);
        // The second Y, Y1
        get_pixels(j->s->block[1], y*8*j->y_rs + 16*x + 8 + y_data, j->y_rs);

        if (!j->bw && j->cheap_upsample) {
                source = y * 4 * j->u_rs + 8*x + u_data;
                dest = j->s->block[2];
                for (i = 0; i < 4; i++) {
                        for (k = 0; k < 8; k++) {
                                dest[k] = source[k];   // First row
                                dest[k+8] = source[k]; // Duplicate to next row

                        }
                        dest += 16;
                        source += j->u_rs;
                }
                source = y * 4 * j->v_rs + 8*x + v_data;
                dest = j->s->block[3];
                for (i = 0; i < 4; i++) {
                        for (k = 0; k < 8; k++) {
                                dest[k] = source[k];
                                dest[k+8] = source[k];
                        }
                        dest += 16;
                        source += j->u_rs;
                }
        } else if (!j->bw && !j->cheap_upsample) {
                // U
                get_pixels(j->s->block[2], y*8*j->u_rs + 8*x + u_data, j->u_rs);
                // V
                get_pixels(j->s->block[3], y*8*j->v_rs + 8*x + v_data, j->v_rs);
        }
}

/**
 * \brief initialize mjpeg encoder
 *
 * This routine is to set up the parameters and initialize the mjpeg encoder.
 * It does all the initializations needed of lower level routines.
 * The formats accepted by this encoder is YUV422P and YUV420
 *
 * \param w width in pixels of the image to encode, must be a multiple of 16
 * \param h height in pixels of the image to encode, must be a multiple of 8
 * \param y_rsize size of each plane row Y component
 * \param y_rsize size of each plane row U component
 * \param v_rsize size of each plane row V component
 * \param cu "cheap upsample". Set to 0 for YUV422 format, 1 for YUV420 format
 *           when set to 1, the encoder will assume that there is only half th
 *           number of rows of chroma information, and every chroma row is
 *           duplicated.
 * \param q quality parameter for the mjpeg encode. Between 1 and 20 where 1
 *          is best quality and 20 is the worst quality.
 * \param b monochrome flag. When set to 1, the mjpeg output is monochrome.
 *          In that case, the colour information is omitted, and actually the
 *          colour planes are not touched.
 *
 * \returns an appropriately set up jpeg_enc_t structure
 *
 * The actual plane buffer addreses are passed by jpeg_enc_frame().
 *
 * The encoder doesn't know anything about interlacing, the halve height
 * needs to be passed and the double rowstride. Which field gets encoded
 * is decided by what buffers are passed to mjpeg_encode_frame()
 */
static jpeg_enc_t *jpeg_enc_init(int w, int h, int y_rsize,
                          int u_rsize, int v_rsize,
                int cu, int q, int b) {
        jpeg_enc_t *j;
        int i = 0;
        VERBOSE("JPEG encoder init: %dx%d %d %d %d cu=%d q=%d bw=%d\n",
                        w, h, y_rsize, u_rsize, v_rsize, cu, q, b);

        j = av_mallocz(sizeof(jpeg_enc_t));
        if (j == NULL) return NULL;

        j->s = av_mallocz(sizeof(MpegEncContext));
        if (j->s == NULL) {
                av_free(j);
                return NULL;
        }

        /* info on how to access the pixels */
        j->y_rs = y_rsize;
        j->u_rs = u_rsize;
        j->v_rs = v_rsize;

        j->s->width = w;                // image width and height
        j->s->height = h;
        j->s->qscale = q;               // Encoding quality

        j->s->mjpeg_data_only_frames = 0;
        j->s->out_format = FMT_MJPEG;
        j->s->intra_only = 1;           // Generate only intra pictures for jpeg
        j->s->encoding = 1;             // Set mode to encode
        j->s->pict_type = I_TYPE;
        j->s->y_dc_scale = 8;
        j->s->c_dc_scale = 8;

        /*
         * This sets up the MCU (Minimal Code Unit) number
         * of appearances of the various component
         * for the SOF0 table in the generated MJPEG.
         * The values are not used for anything else.
         * The current setup is simply YUV422, with two horizontal Y components
         * for every UV component.
         */
        j->s->mjpeg_write_tables = 1;   // setup to write tables
        j->s->mjpeg_vsample[0] = 1;     // 1 appearance of Y vertically
        j->s->mjpeg_vsample[1] = 1;     // 1 appearance of U vertically
        j->s->mjpeg_vsample[2] = 1;     // 1 appearance of V vertically
        j->s->mjpeg_hsample[0] = 2;     // 2 appearances of Y horizontally
        j->s->mjpeg_hsample[1] = 1;     // 1 appearance of U horizontally
        j->s->mjpeg_hsample[2] = 1;     // 1 appearance of V horizontally

        j->cheap_upsample = cu;
        j->bw = b;

        // Is this needed?
        /* if libavcodec is used by the decoder then we must not
         * initialize again, but if it is not initialized then we must
         * initialize it here. */
        if (!avcodec_inited) {
                avcodec_init();
                avcodec_register_all();
                avcodec_inited=1;
        }

        // Build mjpeg huffman code tables, setting up j->s->mjpeg_ctx
        if (mjpeg_init(j->s) < 0) {
                av_free(j->s);
                av_free(j);
                return NULL;
        }

        /* alloc bogus avctx to keep MPV_common_init from segfaulting */
        j->s->avctx = avcodec_alloc_context();
        if (j->s->avctx == NULL) {
                av_free(j->s);
                av_free(j);
                return NULL;
        }

        // Set some a minimum amount of default values that are needed
        // Indicates that we should generated normal MJPEG
        j->s->avctx->codec_id = CODEC_ID_MJPEG;
        // Which DCT method to use. AUTO will select the fastest one
        j->s->avctx->dct_algo = FF_DCT_AUTO;
        j->s->intra_quant_bias= 1<<(QUANT_BIAS_SHIFT-1); //(a + x/2)/x

        j->s->avctx->thread_count = 1;

        /* make MPV_common_init allocate important buffers, like s->block
         * Also initializes dsputil */
        if (MPV_common_init(j->s) < 0) {
                av_free(j->s);
                av_free(j);
                return NULL;
        }

        /* correct the value for sc->mb_height. MPV_common_init put other
         * values there */
        j->s->mb_height = j->s->height/8;
        j->s->mb_intra = 1;

        // Init q matrix
        j->s->intra_matrix[0] = ff_mpeg1_default_intra_matrix[0];
        for (i = 1; i < 64; i++)
                j->s->intra_matrix[i] = av_clip_uint8(
                        (ff_mpeg1_default_intra_matrix[i]*j->s->qscale) >> 3);

        // precompute matrix
        convert_matrix(j->s, j->s->q_intra_matrix, j->s->q_intra_matrix16,
                        j->s->intra_matrix, j->s->intra_quant_bias, 8, 8);

        /* Pick up the selection of the optimal get_pixels() routine
         * to use, which was done in  MPV_common_init() */
        get_pixels = j->s->dsp.get_pixels;

        return j;
}

/**
 * \brief mjpeg encode an image
 *
 * This routine will take a 3-plane YUV422 image and encoded it with MJPEG
 * base line format, as suitable as input for the Zoran hardare MJPEG chips.
 *
 * It requires that the \a j parameter points the structure set up by the
 * jpeg_enc_init() routine.
 *
 * \param j pointer to jpeg_enc_t structure as created by jpeg_enc_init()
 * \param y_data pointer to Y component plane, packed one byte/pixel
 * \param u_data pointer to U component plane, packed one byte per every
 *               other pixel
 * \param v_data pointer to V component plane, packed one byte per every
 *               other pixel
 * \param bufr pointer to the buffer where the mjpeg encoded code is stored
 *
 * \returns the number of bytes stored into \a bufr
 *
 * If \a j->s->mjpeg_write_tables is set, it will also emit the mjpeg tables,
 * otherwise it will just emit the data. The \a j->s->mjpeg_write_tables
 * variable will be reset to 0 by the routine.
 */
static int jpeg_enc_frame(jpeg_enc_t *j, uint8_t *y_data,
                   uint8_t *u_data, uint8_t *v_data, uint8_t *bufr) {
        int mb_x, mb_y, overflow;
        /* initialize the buffer */

        init_put_bits(&j->s->pb, bufr, 1024*256);

        // Emit the mjpeg header blocks
        mjpeg_picture_header(j->s);

        j->s->header_bits = put_bits_count(&j->s->pb);

        j->s->last_dc[0] = 128;
        j->s->last_dc[1] = 128;
        j->s->last_dc[2] = 128;

        for (mb_y = 0; mb_y < j->s->mb_height; mb_y++) {
                for (mb_x = 0; mb_x < j->s->mb_width; mb_x++) {
                        /*
                         * Fill one DCT block (8x8 pixels) from
                         * 2 Y macroblocks and one U and one V
                         */
                        fill_block(j, mb_x, mb_y, y_data, u_data, v_data);
                        emms_c(); /* is this really needed? */

                        j->s->block_last_index[0] =
                                j->s->dct_quantize(j->s, j->s->block[0],
                                                0, 8, &overflow);
                        if (overflow) clip_coeffs(j->s, j->s->block[0],
                                        j->s->block_last_index[0]);
                        j->s->block_last_index[1] =
                                j->s->dct_quantize(j->s, j->s->block[1],
                                                1, 8, &overflow);
                        if (overflow) clip_coeffs(j->s, j->s->block[1],
                                        j->s->block_last_index[1]);

                        if (!j->bw) {
                                j->s->block_last_index[4] =
                                        j->s->dct_quantize(j->s, j->s->block[2],
                                                        4, 8, &overflow);
                                if (overflow) clip_coeffs(j->s, j->s->block[2],
                                                j->s->block_last_index[2]);
                                j->s->block_last_index[5] =
                                        j->s->dct_quantize(j->s, j->s->block[3],
                                                        5, 8, &overflow);
                                if (overflow) clip_coeffs(j->s, j->s->block[3],
                                                j->s->block_last_index[3]);
                        }
                        zr_mjpeg_encode_mb(j);
                }
        }
        emms_c();
        mjpeg_picture_trailer(j->s);
        flush_put_bits(&j->s->pb);

        if (j->s->mjpeg_write_tables == 1)
                j->s->mjpeg_write_tables = 0;

        return pbBufPtr(&(j->s->pb)) - j->s->pb.buf;
}

/// the real uninit routine
/**
 * This is the real routine that does the uninit of the ZRMJPEG filter
 *
 * \param j pointer to jpeg_enc structure
 */
static void jpeg_enc_uninit(jpeg_enc_t *j) {
        mjpeg_close(j->s);
        av_free(j->s);
        av_free(j);
}

/// Private structure for ZRMJPEG filter
struct vf_priv_s {
        jpeg_enc_t *j;
        unsigned char buf[256*1024];
        int bw, fd, hdec, vdec;
        int fields;
        int y_stride;
        int c_stride;
        int quality;
        int maxwidth;
        int maxheight;
};

/// vf CONFIGURE entry point for the ZRMJPEG filter
/**
 * \param vf video filter instance pointer
 * \param width image source width in pixels
 * \param height image source height in pixels
 * \param d_width width of requested window, just a hint
 * \param d_height height of requested window, just a hint
 * \param flags vf filter flags
 * \param outfmt
 *
 * \returns returns 0 on error
 *
 * This routine will make the necessary hardware-related decisions for
 * the ZRMJPEG filter, do the initialization of the MJPEG encoder, and
 * then select one of the ZRJMJPEGIT or ZRMJPEGNI filters and then
 * arrange to dispatch to the config() entry pointer for the one
 * selected.
 */
static int config(struct vf_instance_s* vf, int width, int height, int d_width,
                int d_height, unsigned int flags, unsigned int outfmt){
        struct vf_priv_s *priv = vf->priv;
        float aspect_decision;
        int stretchx, stretchy, err = 0, maxstretchx = 4;
        priv->fields = 1;

        VERBOSE("config() called\n");

        if (priv->j) {
                VERBOSE("re-configuring, resetting JPEG encoder\n");
                jpeg_enc_uninit(priv->j);
                priv->j = NULL;
        }

        aspect_decision = ((float)d_width/(float)d_height)/
                ((float)width/(float)height);

        if (aspect_decision > 1.8 && aspect_decision < 2.2) {
                VERBOSE("should correct aspect by stretching x times 2, %d %d\n", 2*width, priv->maxwidth);
                if (2*width <= priv->maxwidth) {
                        d_width = 2*width;
                        d_height = height;
                        maxstretchx = 2;
                } else {
                        WARNING("unable to correct aspect by stretching, because resulting X will be too large, aspect correction by decimating y not yet implemented\n");
                        d_width = width;
                        d_height = height;
                }
                /* prestretch movie */
        } else {
                /* uncorrecting output for now */
                d_width = width;
                d_height = height;
        }
        /* make the scaling decision
         * we are capable of stretching the image in the horizontal
         * direction by factors 1, 2 and 4
         * we can stretch the image in the vertical direction by a
         * factor of 1 and 2 AND we must decide about interlacing */
        if (d_width > priv->maxwidth/2 || height > priv->maxheight/2
                        || maxstretchx == 1) {
                stretchx = 1;
                stretchy = 1;
                priv->fields = 2;
                if (priv->vdec == 2) {
                        priv->fields = 1;
                } else if (priv->vdec == 4) {
                        priv->fields = 1;
                        stretchy = 2;
                }
                if (priv->hdec > maxstretchx) {
                        if (priv->fd) {
                                WARNING("horizontal decimation too high, "
                                                "changing to %d (use fd to keep"
                                                " hdec=%d)\n",
                                                maxstretchx, priv->hdec);
                                priv->hdec = maxstretchx;
                        }
                }
                stretchx = priv->hdec;
        } else if (d_width > priv->maxwidth/4 ||
                        height > priv->maxheight/4 ||
                        maxstretchx == 2) {
                stretchx = 2;
                stretchy = 1;
                priv->fields = 1;
                if (priv->vdec == 2) {
                        stretchy = 2;
                } else if (priv->vdec == 4) {
                        if (!priv->fd) {
                                WARNING("vertical decimation too high, "
                                                "changing to 2 (use fd to keep "
                                                "vdec=4)\n");
                                priv->vdec = 2;
                        }
                        stretchy = 2;
                }
                if (priv->hdec == 2) {
                        stretchx = 4;
                } else if (priv->hdec == 4) {
                        if (priv->fd) {
                                WARNING("horizontal decimation too high, "
                                                "changing to 2 (use fd to keep "
                                                "hdec=4)\n");
                                priv->hdec = 2;
                        }
                        stretchx = 4;
                }
        } else {
                /* output image is maximally stretched */
                stretchx = 4;
                stretchy = 2;
                priv->fields = 1;
                if (priv->vdec != 1 && !priv->fd) {
                        WARNING("vertical decimation too high, changing to 1 "
                                        "(use fd to keep vdec=%d)\n",
                                        priv->vdec);
                        priv->vdec = 1;
                }
                if (priv->hdec != 1 && !priv->fd) {
                        WARNING("horizontal decimation too high, changing to 1 (use fd to keep hdec=%d)\n", priv->hdec);
                        priv->hdec = 1;
                }
        }

        VERBOSE("generated JPEG's %dx%s%d%s, stretched to %dx%d\n",
                        width/priv->hdec, (priv->fields == 2) ? "(" : "",
                        height/(priv->vdec*priv->fields),
                        (priv->fields == 2) ? "x2)" : "",
                        (width/priv->hdec)*stretchx,
                        (height/(priv->vdec*priv->fields))*
                        stretchy*priv->fields);


        if ((width/priv->hdec)*stretchx > priv->maxwidth ||
                        (height/(priv->vdec*priv->fields))*
                         stretchy*priv->fields  > priv->maxheight) {
                ERROR("output dimensions too large (%dx%d), max (%dx%d) "
                                "insert crop to fix\n",
                                (width/priv->hdec)*stretchx,
                                (height/(priv->vdec*priv->fields))*
                                stretchy*priv->fields,
                                priv->maxwidth, priv->maxheight);
                err = 1;
        }

        if (width%(16*priv->hdec) != 0) {
                ERROR("width must be a multiple of 16*hdec (%d), use expand\n",
                                priv->hdec*16);
                err = 1;
        }

        if (height%(8*priv->fields*priv->vdec) != 0) {
                ERROR("height must be a multiple of 8*fields*vdec (%d),"
                                " use expand\n", priv->vdec*priv->fields*8);
                err = 1;
        }

        if (err) return 0;

        priv->y_stride = width;
        priv->c_stride = width/2;
        priv->j = jpeg_enc_init(width, height/priv->fields,
                                priv->fields*priv->y_stride,
                                priv->fields*priv->c_stride,
                                priv->fields*priv->c_stride,
                                1, priv->quality, priv->bw);

        if (!priv->j) return 0;
        return vf_next_config(vf, width, height, d_width, d_height, flags,
                (priv->fields == 2) ? IMGFMT_ZRMJPEGIT : IMGFMT_ZRMJPEGNI);
}

/// put_image entrypoint for the ZRMJPEG vf filter
/***
 * \param vf pointer to vf_instance
 * \param mpi pointer to mp_image_t structure
 * \param pts
 */
static int put_image(struct vf_instance_s* vf, mp_image_t *mpi, double pts){
        struct vf_priv_s *priv = vf->priv;
        int size = 0;
        int i;
        mp_image_t* dmpi;
        for (i = 0; i < priv->fields; i++)
                size += jpeg_enc_frame(priv->j,
                                mpi->planes[0] + i*priv->y_stride,
                                mpi->planes[1] + i*priv->c_stride,
                                mpi->planes[2] + i*priv->c_stride,
                                priv->buf + size);

        dmpi = vf_get_image(vf->next, IMGFMT_ZRMJPEGNI,
                        MP_IMGTYPE_EXPORT, 0, mpi->w, mpi->h);
        dmpi->planes[0] = (uint8_t*)priv->buf;
        dmpi->planes[1] = (uint8_t*)size;
        return vf_next_put_image(vf,dmpi, pts);
}

/// query_format entrypoint for the ZRMJPEG vf filter
/***
 * \param vf pointer to vf_instance
 * \param fmt image format to query for
 *
 * \returns 0 if image format in fmt is not supported
 *
 * Given the image format specified by \a fmt, this routine is called
 * to ask if the format is supported or not.
 */
static int query_format(struct vf_instance_s* vf, unsigned int fmt){
        VERBOSE("query_format() called\n");

        switch (fmt) {
                case IMGFMT_YV12:
                case IMGFMT_YUY2:
                        /* strictly speaking the output format of
                         * this filter will be known after config(),
                         * but everything that supports IMGFMT_ZRMJPEGNI
                         * should also support all other IMGFMT_ZRMJPEG* */
                        return vf_next_query_format(vf, IMGFMT_ZRMJPEGNI);
        }

        return 0;
}

/// vf UNINIT entry point for the ZRMJPEG filter
/**
 * \param vf pointer to the vf instance structure
 */
static void uninit(vf_instance_t *vf) {
        struct vf_priv_s *priv = vf->priv;
        VERBOSE("uninit() called\n");
        if (priv->j) jpeg_enc_uninit(priv->j);
        free(priv);
}

/// vf OPEN entry point for the ZRMJPEG filter
/**
 * \param vf pointer to the vf instance structure
 * \param args the argument list string for the -vf zrmjpeg command
 *
 * \returns 0 for error, 1 for success
 *
 * This routine will do some basic initialization of local structures etc.,
 * and then parse the command line arguments specific for the ZRMJPEG filter.
 */
static int open(vf_instance_t *vf, char* args){
        struct vf_priv_s *priv;
        VERBOSE("open() called: args=\"%s\"\n", args);

        vf->config = config;
        vf->put_image = put_image;
        vf->query_format = query_format;
        vf->uninit = uninit;

        priv = vf->priv = calloc(sizeof(*priv), 1);
        if (!vf->priv) {
                ERROR("out of memory error\n");
                return 0;
        }

        /* maximum displayable size by zoran card, these defaults
         * are for my own zoran card in PAL mode, these can be changed
         * by filter options. But... in an ideal world these values would
         * be queried from the vo device itself... */
        priv->maxwidth = 768;
        priv->maxheight = 576;

        priv->quality = 2;
        priv->hdec = 1;
        priv->vdec = 1;

        /* if libavcodec is already initialized, we must not initialize it
         * again, but if it is not initialized then we mustinitialize it now. */
        if (!avcodec_inited) {
                /* we need to initialize libavcodec */
                avcodec_init();
                avcodec_register_all();
                avcodec_inited=1;
        }

        if (args) {
                char *arg, *tmp, *ptr, junk;
                int last = 0, input;

                /* save arguments, to be able to safely modify them */
                arg = strdup(args);
                if (!arg) {
                        ERROR("out of memory, this is bad\n");
                        return 0;
                }

                tmp = ptr = arg;
                do {
                        while (*tmp != ':' && *tmp) tmp++;
                        if (*tmp == ':') *tmp++ = '\0';
                        else last = 1;
                        VERBOSE("processing filter option \"%s\"\n", ptr);
                        /* These options deal with the maximum output
                         * resolution of the zoran card. These should
                         * be queried from the vo device, but it is currently
                         * too difficult, so the user should tell the filter */
                        if (!strncmp("maxheight=", ptr, 10)) {
                                if (sscanf(ptr+10, "%d%c", &input, &junk) != 1)
                                                ERROR(
                "error parsing parameter to \"maxheight=\", \"%s\", ignoring\n"
                                                                , ptr + 10);
                                else {
                                        priv->maxheight = input;
                                        VERBOSE("setting maxheight to %d\n",
                                                        priv->maxheight);
                                }
                        } else if (!strncmp("quality=", ptr, 8)) {
                                if (sscanf(ptr+8, "%d%c", &input, &junk) != 1)
                                        ERROR(
                "error parsing parameter to \"quality=\", \"%s\", ignoring\n"
                                                                , ptr + 8);
                                else if (input < 1 || input > 20)
                                        ERROR(
                "parameter to \"quality=\" out of range (1..20), %d\n", input);
                                else {
                                        priv->quality = input;
                                        VERBOSE("setting JPEG quality to %d\n",
                                                        priv->quality);
                                }
                        } else if (!strncmp("maxwidth=", ptr, 9)) {
                                if (sscanf(ptr+9, "%d%c", &input, &junk) != 1)
                                        ERROR(
                "error parsing parameter to \"maxwidth=\", \"%s\", ignoring\n"
                                                                , ptr + 9);
                                else {
                                        priv->maxwidth = input;
                                        VERBOSE("setting maxwidth to %d\n",
                                                        priv->maxwidth);
                                }
                        } else if (!strncmp("hdec=", ptr, 5)) {
                                if (sscanf(ptr+5, "%d%c", &input, &junk) != 1)
                                        ERROR(
                "error parsing parameter to \"hdec=\", \"%s\", ignoring\n"
                                                                , ptr + 9);
                                else if (input != 1 && input != 2 && input != 4)
                                        ERROR(
                "illegal parameter to \"hdec=\", %d, should be 1, 2 or 4",
                                                                input);
                                else {
                                        priv->hdec = input;
                                        VERBOSE(
                "setting horizontal decimation to %d\n", priv->maxwidth);
                                }
                        } else if (!strncmp("vdec=", ptr, 5)) {
                                if (sscanf(ptr+5, "%d%c", &input, &junk) != 1)
                                        ERROR(
                "error parsing parameter to \"vdec=\", \"%s\", ignoring\n"
                                                                , ptr + 9);
                                else if (input != 1 && input != 2 && input != 4)
                                        ERROR(
                "illegal parameter to \"vdec=\", %d, should be 1, 2 or 4",
                                                                input);
                                else {
                                        priv->vdec = input;
                                        VERBOSE(
                        "setting vertical decimation to %d\n", priv->maxwidth);
                                }
                        } else if (!strcasecmp("dc10+-PAL", ptr) ||
                                        !strcasecmp("dc10-PAL", ptr)) {
                                priv->maxwidth = 768;
                                priv->maxheight = 576;
                                VERBOSE("setting DC10(+) PAL profile\n");
                        } else if (!strcasecmp("fd", ptr)) {
                                priv->fd = 1;
                                VERBOSE("forcing decimation\n");
                        } else if (!strcasecmp("nofd", ptr)) {
                                priv->fd = 0;
                                VERBOSE("decimate only if beautiful\n");
                        } else if (!strcasecmp("bw", ptr)) {
                                priv->bw = 1;
                                VERBOSE("setting black and white encoding\n");
                        } else if (!strcasecmp("color", ptr)) {
                                priv->bw = 0;
                                VERBOSE("setting color encoding\n");
                        } else if (!strcasecmp("dc10+-NTSC", ptr) ||
                                        !strcasecmp("dc10-NTSC", ptr)) {
                                priv->maxwidth = 640;
                                priv->maxheight = 480;
                                VERBOSE("setting DC10(+) NTSC profile\n");
                        } else if (!strcasecmp("buz-PAL", ptr) ||
                                        !strcasecmp("lml33-PAL", ptr)) {
                                priv->maxwidth = 720;
                                priv->maxheight = 576;
                                VERBOSE("setting buz/lml33 PAL profile\n");
                        } else if (!strcasecmp("buz-NTSC", ptr) ||
                                        !strcasecmp("lml33-NTSC", ptr)) {
                                priv->maxwidth = 720;
                                priv->maxheight = 480;
                                VERBOSE("setting buz/lml33 NTSC profile\n");
                        } else {
                                WARNING("ignoring unknown filter option "
                                                "\"%s\", or missing argument\n",
                                                ptr);
                        }
                        ptr = tmp;
                } while (!last);

                free(arg);
        }


        return 1;
}

vf_info_t vf_info_zrmjpeg = {
    "realtime zoran MJPEG encoding",
    "zrmjpeg",
    "Rik Snel",
    "",
    open,
    NULL
};