LCOV - code coverage report
Current view: top level - libavcodec - flashsvenc.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 88 108 81.5 %
Date: 2017-12-17 23:02:56 Functions: 5 5 100.0 %

          Line data    Source code
       1             : /*
       2             :  * Flash Screen Video encoder
       3             :  * Copyright (C) 2004 Alex Beregszaszi
       4             :  * Copyright (C) 2006 Benjamin Larsson
       5             :  *
       6             :  * This file is part of FFmpeg.
       7             :  *
       8             :  * FFmpeg is free software; you can redistribute it and/or
       9             :  * modify it under the terms of the GNU Lesser General Public
      10             :  * License as published by the Free Software Foundation; either
      11             :  * version 2.1 of the License, or (at your option) any later version.
      12             :  *
      13             :  * FFmpeg is distributed in the hope that it will be useful,
      14             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      15             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      16             :  * Lesser General Public License for more details.
      17             :  *
      18             :  * You should have received a copy of the GNU Lesser General Public
      19             :  * License along with FFmpeg; if not, write to the Free Software
      20             :  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
      21             :  */
      22             : 
      23             : /* Encoding development sponsored by http://fh-campuswien.ac.at */
      24             : 
      25             : /**
      26             :  * @file
      27             :  * Flash Screen Video encoder
      28             :  * @author Alex Beregszaszi
      29             :  * @author Benjamin Larsson
      30             :  *
      31             :  * A description of the bitstream format for Flash Screen Video version 1/2
      32             :  * is part of the SWF File Format Specification (version 10), which can be
      33             :  * downloaded from http://www.adobe.com/devnet/swf.html.
      34             :  */
      35             : 
      36             : /*
      37             :  * Encoding ideas: A basic encoder would just use a fixed block size.
      38             :  * Block sizes can be multiples of 16, from 16 to 256. The blocks don't
      39             :  * have to be quadratic. A brute force search with a set of different
      40             :  * block sizes should give a better result than to just use a fixed size.
      41             :  *
      42             :  * TODO:
      43             :  * Don't reencode the frame in brute force mode if the frame is a dupe.
      44             :  * Speed up. Make the difference check faster.
      45             :  */
      46             : 
      47             : #include <stdio.h>
      48             : #include <stdlib.h>
      49             : #include <zlib.h>
      50             : 
      51             : #include "avcodec.h"
      52             : #include "internal.h"
      53             : #include "put_bits.h"
      54             : #include "bytestream.h"
      55             : 
      56             : 
      57             : typedef struct FlashSVContext {
      58             :     AVCodecContext *avctx;
      59             :     uint8_t        *previous_frame;
      60             :     int             image_width, image_height;
      61             :     int             block_width, block_height;
      62             :     uint8_t        *tmpblock;
      63             :     uint8_t        *encbuffer;
      64             :     int             block_size;
      65             :     z_stream        zstream;
      66             :     int             last_key_frame;
      67             : } FlashSVContext;
      68             : 
      69        4550 : static int copy_region_enc(uint8_t *sptr, uint8_t *dptr, int dx, int dy,
      70             :                            int h, int w, int stride, uint8_t *pfptr)
      71             : {
      72             :     int i, j;
      73             :     uint8_t *nsptr;
      74             :     uint8_t *npfptr;
      75        4550 :     int diff = 0;
      76             : 
      77      265450 :     for (i = dx + h; i > dx; i--) {
      78      260900 :         nsptr  = sptr  + i * stride + dy * 3;
      79      260900 :         npfptr = pfptr + i * stride + dy * 3;
      80    46053500 :         for (j = 0; j < w * 3; j++) {
      81    45792600 :             diff    |= npfptr[j] ^ nsptr[j];
      82    45792600 :             dptr[j]  = nsptr[j];
      83             :         }
      84      260900 :         dptr += w * 3;
      85             :     }
      86        4550 :     if (diff)
      87        4550 :         return 1;
      88           0 :     return 0;
      89             : }
      90             : 
      91           4 : static av_cold int flashsv_encode_end(AVCodecContext *avctx)
      92             : {
      93           4 :     FlashSVContext *s = avctx->priv_data;
      94             : 
      95           4 :     deflateEnd(&s->zstream);
      96             : 
      97           4 :     av_freep(&s->encbuffer);
      98           4 :     av_freep(&s->previous_frame);
      99           4 :     av_freep(&s->tmpblock);
     100             : 
     101           4 :     return 0;
     102             : }
     103             : 
     104           4 : static av_cold int flashsv_encode_init(AVCodecContext *avctx)
     105             : {
     106           4 :     FlashSVContext *s = avctx->priv_data;
     107             : 
     108           4 :     s->avctx = avctx;
     109             : 
     110           4 :     if (avctx->width > 4095 || avctx->height > 4095) {
     111           0 :         av_log(avctx, AV_LOG_ERROR,
     112             :                "Input dimensions too large, input must be max 4095x4095 !\n");
     113           0 :         return AVERROR_INVALIDDATA;
     114             :     }
     115             : 
     116             :     // Needed if zlib unused or init aborted before deflateInit
     117           4 :     memset(&s->zstream, 0, sizeof(z_stream));
     118             : 
     119           4 :     s->last_key_frame = 0;
     120             : 
     121           4 :     s->image_width  = avctx->width;
     122           4 :     s->image_height = avctx->height;
     123             : 
     124           4 :     s->tmpblock  = av_mallocz(3 * 256 * 256);
     125           4 :     s->encbuffer = av_mallocz(s->image_width * s->image_height * 3);
     126             : 
     127           4 :     if (!s->tmpblock || !s->encbuffer) {
     128           0 :         av_log(avctx, AV_LOG_ERROR, "Memory allocation failed.\n");
     129           0 :         return AVERROR(ENOMEM);
     130             :     }
     131             : 
     132           4 :     return 0;
     133             : }
     134             : 
     135             : 
     136         200 : static int encode_bitstream(FlashSVContext *s, const AVFrame *p, uint8_t *buf,
     137             :                             int buf_size, int block_width, int block_height,
     138             :                             uint8_t *previous_frame, int *I_frame)
     139             : {
     140             : 
     141             :     PutBitContext pb;
     142             :     int h_blocks, v_blocks, h_part, v_part, i, j;
     143             :     int buf_pos, res;
     144         200 :     int pred_blocks = 0;
     145             : 
     146         200 :     init_put_bits(&pb, buf, buf_size);
     147             : 
     148         200 :     put_bits(&pb,  4, block_width / 16 - 1);
     149         200 :     put_bits(&pb, 12, s->image_width);
     150         200 :     put_bits(&pb,  4, block_height / 16 - 1);
     151         200 :     put_bits(&pb, 12, s->image_height);
     152         200 :     flush_put_bits(&pb);
     153         200 :     buf_pos = 4;
     154             : 
     155         200 :     h_blocks = s->image_width  / block_width;
     156         200 :     h_part   = s->image_width  % block_width;
     157         200 :     v_blocks = s->image_height / block_height;
     158         200 :     v_part   = s->image_height % block_height;
     159             : 
     160             :     /* loop over all block columns */
     161        1000 :     for (j = 0; j < v_blocks + (v_part ? 1 : 0); j++) {
     162             : 
     163         800 :         int y_pos = j * block_height; // vertical position in frame
     164         800 :         int cur_blk_height = (j < v_blocks) ? block_height : v_part;
     165             : 
     166             :         /* loop over all block rows */
     167        5350 :         for (i = 0; i < h_blocks + (h_part ? 1 : 0); i++) {
     168        4550 :             int x_pos = i * block_width; // horizontal position in frame
     169        4550 :             int cur_blk_width = (i < h_blocks) ? block_width : h_part;
     170        4550 :             int ret = Z_OK;
     171        4550 :             uint8_t *ptr = buf + buf_pos;
     172             : 
     173             :             /* copy the block to the temp buffer before compression
     174             :              * (if it differs from the previous frame's block) */
     175        9100 :             res = copy_region_enc(p->data[0], s->tmpblock,
     176        4550 :                                   s->image_height - (y_pos + cur_blk_height + 1),
     177             :                                   x_pos, cur_blk_height, cur_blk_width,
     178             :                                   p->linesize[0], previous_frame);
     179             : 
     180        9100 :             if (res || *I_frame) {
     181        4550 :                 unsigned long zsize = 3 * block_width * block_height;
     182        4550 :                 ret = compress2(ptr + 2, &zsize, s->tmpblock,
     183        4550 :                                 3 * cur_blk_width * cur_blk_height, 9);
     184             : 
     185             :                 //ret = deflateReset(&s->zstream);
     186        4550 :                 if (ret != Z_OK)
     187           0 :                     av_log(s->avctx, AV_LOG_ERROR,
     188             :                            "error while compressing block %dx%d\n", i, j);
     189             : 
     190        4550 :                 bytestream_put_be16(&ptr, zsize);
     191        4550 :                 buf_pos += zsize + 2;
     192             :                 ff_dlog(s->avctx, "buf_pos = %d\n", buf_pos);
     193             :             } else {
     194           0 :                 pred_blocks++;
     195           0 :                 bytestream_put_be16(&ptr, 0);
     196           0 :                 buf_pos += 2;
     197             :             }
     198             :         }
     199             :     }
     200             : 
     201         200 :     if (pred_blocks)
     202           0 :         *I_frame = 0;
     203             :     else
     204         200 :         *I_frame = 1;
     205             : 
     206         200 :     return buf_pos;
     207             : }
     208             : 
     209             : 
     210         200 : static int flashsv_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
     211             :                                 const AVFrame *pict, int *got_packet)
     212             : {
     213         200 :     FlashSVContext * const s = avctx->priv_data;
     214         200 :     const AVFrame * const p = pict;
     215             :     uint8_t *pfptr;
     216             :     int res;
     217         200 :     int I_frame = 0;
     218         200 :     int opt_w = 4, opt_h = 4;
     219             : 
     220             :     /* First frame needs to be a keyframe */
     221         200 :     if (avctx->frame_number == 0) {
     222           4 :         s->previous_frame = av_mallocz(FFABS(p->linesize[0]) * s->image_height);
     223           4 :         if (!s->previous_frame) {
     224           0 :             av_log(avctx, AV_LOG_ERROR, "Memory allocation failed.\n");
     225           0 :             return AVERROR(ENOMEM);
     226             :         }
     227           4 :         I_frame = 1;
     228             :     }
     229             : 
     230         200 :     if (p->linesize[0] < 0)
     231           0 :         pfptr = s->previous_frame - (s->image_height - 1) * p->linesize[0];
     232             :     else
     233         200 :         pfptr = s->previous_frame;
     234             : 
     235             :     /* Check the placement of keyframes */
     236         400 :     if (avctx->gop_size > 0 &&
     237         200 :         avctx->frame_number >= s->last_key_frame + avctx->gop_size) {
     238           0 :         I_frame = 1;
     239             :     }
     240             : 
     241         200 :     if ((res = ff_alloc_packet2(avctx, pkt, s->image_width * s->image_height * 3, 0)) < 0)
     242           0 :         return res;
     243             : 
     244         200 :     pkt->size = encode_bitstream(s, p, pkt->data, pkt->size, opt_w * 16, opt_h * 16,
     245             :                                  pfptr, &I_frame);
     246             : 
     247             :     //save the current frame
     248         200 :     if (p->linesize[0] > 0)
     249         200 :         memcpy(s->previous_frame, p->data[0], s->image_height * p->linesize[0]);
     250             :     else
     251           0 :         memcpy(s->previous_frame,
     252           0 :                p->data[0] + p->linesize[0] * (s->image_height - 1),
     253           0 :                s->image_height * FFABS(p->linesize[0]));
     254             : 
     255             :     //mark the frame type so the muxer can mux it correctly
     256         200 :     if (I_frame) {
     257             : #if FF_API_CODED_FRAME
     258             : FF_DISABLE_DEPRECATION_WARNINGS
     259         200 :         avctx->coded_frame->pict_type      = AV_PICTURE_TYPE_I;
     260         200 :         avctx->coded_frame->key_frame      = 1;
     261             : FF_ENABLE_DEPRECATION_WARNINGS
     262             : #endif
     263         200 :         s->last_key_frame = avctx->frame_number;
     264             :         ff_dlog(avctx, "Inserting keyframe at frame %d\n", avctx->frame_number);
     265             :     } else {
     266             : #if FF_API_CODED_FRAME
     267             : FF_DISABLE_DEPRECATION_WARNINGS
     268           0 :         avctx->coded_frame->pict_type = AV_PICTURE_TYPE_P;
     269           0 :         avctx->coded_frame->key_frame = 0;
     270             : FF_ENABLE_DEPRECATION_WARNINGS
     271             : #endif
     272             :     }
     273             : 
     274         200 :     if (I_frame)
     275         200 :         pkt->flags |= AV_PKT_FLAG_KEY;
     276         200 :     *got_packet = 1;
     277             : 
     278         200 :     return 0;
     279             : }
     280             : 
     281             : AVCodec ff_flashsv_encoder = {
     282             :     .name           = "flashsv",
     283             :     .long_name      = NULL_IF_CONFIG_SMALL("Flash Screen Video"),
     284             :     .type           = AVMEDIA_TYPE_VIDEO,
     285             :     .id             = AV_CODEC_ID_FLASHSV,
     286             :     .priv_data_size = sizeof(FlashSVContext),
     287             :     .init           = flashsv_encode_init,
     288             :     .encode2        = flashsv_encode_frame,
     289             :     .close          = flashsv_encode_end,
     290             :     .pix_fmts       = (const enum AVPixelFormat[]){ AV_PIX_FMT_BGR24, AV_PIX_FMT_NONE },
     291             : };

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