qtrleenc.c 11.2 KB
Newer Older
Alexis Ballier's avatar
Alexis Ballier committed
1 2 3 4 5
/*
 * Quicktime Animation (RLE) Video Encoder
 * Copyright (C) 2007 Clemens Fruhwirth
 * Copyright (C) 2007 Alexis Ballier
 *
6
 * This file is based on flashsvenc.c.
Alexis Ballier's avatar
Alexis Ballier committed
7
 *
8
 * This file is part of Libav.
Alexis Ballier's avatar
Alexis Ballier committed
9
 *
10
 * Libav is free software; you can redistribute it and/or
Alexis Ballier's avatar
Alexis Ballier committed
11
 * modify it under the terms of the GNU Lesser General Public
12 13
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
Alexis Ballier's avatar
Alexis Ballier committed
14
 *
15
 * Libav is distributed in the hope that it will be useful,
Alexis Ballier's avatar
Alexis Ballier committed
16 17 18 19 20
 * 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
21
 * License along with Libav; if not, write to the Free Software
Alexis Ballier's avatar
Alexis Ballier committed
22 23 24
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

25
#include "libavutil/imgutils.h"
Alexis Ballier's avatar
Alexis Ballier committed
26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61
#include "avcodec.h"
#include "bytestream.h"

/** Maximum RLE code for bulk copy */
#define MAX_RLE_BULK   127
/** Maximum RLE code for repeat */
#define MAX_RLE_REPEAT 128
/** Maximum RLE code for skip */
#define MAX_RLE_SKIP   254

typedef struct QtrleEncContext {
    AVCodecContext *avctx;
    AVFrame frame;
    int pixel_size;
    AVPicture previous_frame;
    unsigned int max_buf_size;
    /**
     * This array will contain at ith position the value of the best RLE code
     * if the line started at pixel i
     * There can be 3 values :
     * skip (0)     : skip as much as possible pixels because they are equal to the
     *                previous frame ones
     * repeat (<-1) : repeat that pixel -rle_code times, still as much as
     *                possible
     * copy (>0)    : copy the raw next rle_code pixels */
    signed char *rlecode_table;
    /**
     * This array will contain the length of the best rle encoding of the line
     * starting at ith pixel */
    int *length_table;
    /**
     * Will contain at ith position the number of consecutive pixels equal to the previous
     * frame starting from pixel i */
    uint8_t* skip_table;
} QtrleEncContext;

62
static av_cold int qtrle_encode_init(AVCodecContext *avctx)
Alexis Ballier's avatar
Alexis Ballier committed
63 64 65
{
    QtrleEncContext *s = avctx->priv_data;

66
    if (av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
Alexis Ballier's avatar
Alexis Ballier committed
67 68 69 70 71
        return -1;
    }
    s->avctx=avctx;

    switch (avctx->pix_fmt) {
72
    case PIX_FMT_RGB555BE:
Alexis Ballier's avatar
Alexis Ballier committed
73
        s->pixel_size = 2;
74
        break;
Alexis Ballier's avatar
Alexis Ballier committed
75 76 77
    case PIX_FMT_RGB24:
        s->pixel_size = 3;
        break;
78 79 80
    case PIX_FMT_ARGB:
        s->pixel_size = 4;
        break;
Alexis Ballier's avatar
Alexis Ballier committed
81 82 83 84
    default:
        av_log(avctx, AV_LOG_ERROR, "Unsupported colorspace.\n");
        break;
    }
85
    avctx->bits_per_coded_sample = s->pixel_size*8;
Alexis Ballier's avatar
Alexis Ballier committed
86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107

    s->rlecode_table = av_mallocz(s->avctx->width);
    s->skip_table    = av_mallocz(s->avctx->width);
    s->length_table  = av_mallocz((s->avctx->width + 1)*sizeof(int));
    if (!s->skip_table || !s->length_table || !s->rlecode_table) {
        av_log(avctx, AV_LOG_ERROR, "Error allocating memory.\n");
        return -1;
    }
    if (avpicture_alloc(&s->previous_frame, avctx->pix_fmt, avctx->width, avctx->height) < 0) {
        av_log(avctx, AV_LOG_ERROR, "Error allocating picture\n");
        return -1;
    }

    s->max_buf_size = s->avctx->width*s->avctx->height*s->pixel_size /* image base material */
                      + 15                                           /* header + footer */
                      + s->avctx->height*2                           /* skip code+rle end */
                      + s->avctx->width/MAX_RLE_BULK + 1             /* rle codes */;
    avctx->coded_frame = &s->frame;
    return 0;
}

/**
108
 * Compute the best RLE sequence for a line
Alexis Ballier's avatar
Alexis Ballier committed
109 110 111 112 113 114 115 116 117 118 119 120 121 122
 */
static void qtrle_encode_line(QtrleEncContext *s, AVFrame *p, int line, uint8_t **buf)
{
    int width=s->avctx->width;
    int i;
    signed char rlecode;

    /* We will use it to compute the best bulk copy sequence */
    unsigned int bulkcount;
    /* This will be the number of pixels equal to the preivous frame one's
     * starting from the ith pixel */
    unsigned int skipcount;
    /* This will be the number of consecutive equal pixels in the current
     * frame, starting from the ith one also */
123
    unsigned int av_uninit(repeatcount);
Alexis Ballier's avatar
Alexis Ballier committed
124 125 126 127 128 129 130 131 132

    /* The cost of the three different possibilities */
    int total_bulk_cost;
    int total_skip_cost;
    int total_repeat_cost;

    int temp_cost;
    int j;

133 134 135 136
    uint8_t *this_line = p->               data[0] + line*p->               linesize[0] +
        (width - 1)*s->pixel_size;
    uint8_t *prev_line = s->previous_frame.data[0] + line*s->previous_frame.linesize[0] +
        (width - 1)*s->pixel_size;
Alexis Ballier's avatar
Alexis Ballier committed
137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238

    s->length_table[width] = 0;
    skipcount = 0;

    for (i = width - 1; i >= 0; i--) {

        if (!s->frame.key_frame && !memcmp(this_line, prev_line, s->pixel_size))
            skipcount = FFMIN(skipcount + 1, MAX_RLE_SKIP);
        else
            skipcount = 0;

        total_skip_cost  = s->length_table[i + skipcount] + 2;
        s->skip_table[i] = skipcount;


        if (i < width - 1 && !memcmp(this_line, this_line + s->pixel_size, s->pixel_size))
            repeatcount = FFMIN(repeatcount + 1, MAX_RLE_REPEAT);
        else
            repeatcount = 1;

        total_repeat_cost = s->length_table[i + repeatcount] + 1 + s->pixel_size;

        /* skip code is free for the first pixel, it costs one byte for repeat and bulk copy
         * so let's make it aware */
        if (i == 0) {
            total_skip_cost--;
            total_repeat_cost++;
        }

        if (repeatcount > 1 && (skipcount == 0 || total_repeat_cost < total_skip_cost)) {
            /* repeat is the best */
            s->length_table[i]  = total_repeat_cost;
            s->rlecode_table[i] = -repeatcount;
        }
        else if (skipcount > 0) {
            /* skip is the best choice here */
            s->length_table[i]  = total_skip_cost;
            s->rlecode_table[i] = 0;
        }
        else {
            /* We cannot do neither skip nor repeat
             * thus we search for the best bulk copy to do */

            int limit = FFMIN(width - i, MAX_RLE_BULK);

            temp_cost = 1 + s->pixel_size + !i;
            total_bulk_cost = INT_MAX;

            for (j = 1; j <= limit; j++) {
                if (s->length_table[i + j] + temp_cost < total_bulk_cost) {
                    /* We have found a better bulk copy ... */
                    total_bulk_cost = s->length_table[i + j] + temp_cost;
                    bulkcount = j;
                }
                temp_cost += s->pixel_size;
            }

            s->length_table[i]  = total_bulk_cost;
            s->rlecode_table[i] = bulkcount;
        }

        this_line -= s->pixel_size;
        prev_line -= s->pixel_size;
    }

    /* Good ! Now we have the best sequence for this line, let's ouput it */

    /* We do a special case for the first pixel so that we avoid testing it in
     * the whole loop */

    i=0;
    this_line = p->               data[0] + line*p->linesize[0];

    if (s->rlecode_table[0] == 0) {
        bytestream_put_byte(buf, s->skip_table[0] + 1);
        i += s->skip_table[0];
    }
    else bytestream_put_byte(buf, 1);


    while (i < width) {
        rlecode = s->rlecode_table[i];
        bytestream_put_byte(buf, rlecode);
        if (rlecode == 0) {
            /* Write a skip sequence */
            bytestream_put_byte(buf, s->skip_table[i] + 1);
            i += s->skip_table[i];
        }
        else if (rlecode > 0) {
            /* bulk copy */
            bytestream_put_buffer(buf, this_line + i*s->pixel_size, rlecode*s->pixel_size);
            i += rlecode;
        }
        else {
            /* repeat the bits */
            bytestream_put_buffer(buf, this_line + i*s->pixel_size, s->pixel_size);
            i -= rlecode;
        }
    }
    bytestream_put_byte(buf, -1); // end RLE line
}

239
/** Encode frame including header */
Alexis Ballier's avatar
Alexis Ballier committed
240 241 242 243 244 245 246 247
static int encode_frame(QtrleEncContext *s, AVFrame *p, uint8_t *buf)
{
    int i;
    int start_line = 0;
    int end_line = s->avctx->height;
    uint8_t *orig_buf = buf;

    if (!s->frame.key_frame) {
248
        unsigned line_size = s->avctx->width * s->pixel_size;
Alexis Ballier's avatar
Alexis Ballier committed
249 250
        for (start_line = 0; start_line < s->avctx->height; start_line++)
            if (memcmp(p->data[0] + start_line*p->linesize[0],
251 252
                       s->previous_frame.data[0] + start_line*s->previous_frame.linesize[0],
                       line_size))
Alexis Ballier's avatar
Alexis Ballier committed
253 254 255 256
                break;

        for (end_line=s->avctx->height; end_line > start_line; end_line--)
            if (memcmp(p->data[0] + (end_line - 1)*p->linesize[0],
257 258
                       s->previous_frame.data[0] + (end_line - 1)*s->previous_frame.linesize[0],
                       line_size))
Alexis Ballier's avatar
Alexis Ballier committed
259 260 261 262 263
                break;
    }

    bytestream_put_be32(&buf, 0);                         // CHUNK SIZE, patched later

264
    if ((start_line == 0 && end_line == s->avctx->height) || start_line == s->avctx->height)
Alexis Ballier's avatar
Alexis Ballier committed
265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297
        bytestream_put_be16(&buf, 0);                     // header
    else {
        bytestream_put_be16(&buf, 8);                     // header
        bytestream_put_be16(&buf, start_line);            // starting line
        bytestream_put_be16(&buf, 0);                     // unknown
        bytestream_put_be16(&buf, end_line - start_line); // lines to update
        bytestream_put_be16(&buf, 0);                     // unknown
    }
    for (i = start_line; i < end_line; i++)
        qtrle_encode_line(s, p, i, &buf);

    bytestream_put_byte(&buf, 0);                         // zero skip code = frame finished
    AV_WB32(orig_buf, buf - orig_buf);                    // patch the chunk size
    return buf - orig_buf;
}

static int qtrle_encode_frame(AVCodecContext *avctx, uint8_t *buf, int buf_size, void *data)
{
    QtrleEncContext * const s = avctx->priv_data;
    AVFrame *pict = data;
    AVFrame * const p = &s->frame;
    int chunksize;

    *p = *pict;

    if (buf_size < s->max_buf_size) {
        /* Upper bound check for compressed data */
        av_log(avctx, AV_LOG_ERROR, "buf_size %d <  %d\n", buf_size, s->max_buf_size);
        return -1;
    }

    if (avctx->gop_size == 0 || (s->avctx->frame_number % avctx->gop_size) == 0) {
        /* I-Frame */
298
        p->pict_type = AV_PICTURE_TYPE_I;
Alexis Ballier's avatar
Alexis Ballier committed
299 300 301
        p->key_frame = 1;
    } else {
        /* P-Frame */
302
        p->pict_type = AV_PICTURE_TYPE_P;
Alexis Ballier's avatar
Alexis Ballier committed
303 304 305 306 307 308 309 310 311 312
        p->key_frame = 0;
    }

    chunksize = encode_frame(s, pict, buf);

    /* save the current frame */
    av_picture_copy(&s->previous_frame, (AVPicture *)p, avctx->pix_fmt, avctx->width, avctx->height);
    return chunksize;
}

313
static av_cold int qtrle_encode_end(AVCodecContext *avctx)
Alexis Ballier's avatar
Alexis Ballier committed
314 315 316 317 318 319 320 321 322 323
{
    QtrleEncContext *s = avctx->priv_data;

    avpicture_free(&s->previous_frame);
    av_free(s->rlecode_table);
    av_free(s->length_table);
    av_free(s->skip_table);
    return 0;
}

324
AVCodec ff_qtrle_encoder = {
325 326 327 328 329 330 331
    .name           = "qtrle",
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = CODEC_ID_QTRLE,
    .priv_data_size = sizeof(QtrleEncContext),
    .init           = qtrle_encode_init,
    .encode         = qtrle_encode_frame,
    .close          = qtrle_encode_end,
332
    .pix_fmts = (const enum PixelFormat[]){PIX_FMT_RGB24, PIX_FMT_RGB555BE, PIX_FMT_ARGB, PIX_FMT_NONE},
333
    .long_name = NULL_IF_CONFIG_SMALL("QuickTime Animation (RLE) video"),
Alexis Ballier's avatar
Alexis Ballier committed
334
};