mjpegencoder.cpp

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/*
    Copyright (C) 2017 by Jasem Mutlaq <mutlaqja@ikarustech.com>
 
    INDI Raw Encoder
 
    This library 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.
 
    This library 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 this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 
*/
 
#include "mjpegencoder.h"
#include "stream/streammanager.h"
#include "indiccd.h"
#include <cmath>
#include <zlib.h>
#include <jpeglib.h>
#include <jerror.h>
 
static void init_destination(j_compress_ptr cinfo)
{
    INDI_UNUSED(cinfo);
    /* No work necessary here */
}
 
static boolean empty_output_buffer(j_compress_ptr cinfo)
{
    INDI_UNUSED(cinfo);
    /* No work necessary here */
    return TRUE;
}
 
static void term_destination(j_compress_ptr cinfo)
{
    INDI_UNUSED(cinfo);
    /* no work necessary here */
}
 
namespace INDI
{
 
MJPEGEncoder::MJPEGEncoder()
{
    name = "MJPEG";
}
 
MJPEGEncoder::~MJPEGEncoder()
{
    delete [] jpegBuffer;
}
 
const char *MJPEGEncoder::getDeviceName()
{
    return currentDevice->getDeviceName();
}
 
bool MJPEGEncoder::upload(INDI::WidgetViewBlob *bp, const uint8_t *buffer, uint32_t nbytes, bool isCompressed)
{
    // We do not support compression
    if (isCompressed)
    {
        LOG_ERROR("Compression is not supported in MJPEG stream.");
        return false;
    }
 
    INDI_UNUSED(nbytes);
    int bufsize = rawWidth * rawHeight * ((pixelFormat == INDI_RGB) ? 3 : 1);
    if (bufsize != jpegBufferSize)
    {
        delete [] jpegBuffer;
        jpegBuffer = new uint8_t[bufsize];
        jpegBufferSize = bufsize;
    }
 
    // Scale image DOWN by this factor
    // 640 is now selected arbitrary to test mpeg streaming performance
    int scale = std::max(1, static_cast<int>(std::floor(rawWidth / SCALE_WIDTH)));
    if (pixelFormat == INDI_RGB)
        jpeg_compress_8u_rgb(buffer, rawWidth, rawHeight, rawWidth * 3, scale, jpegBuffer, &bufsize, 85);
    else
        jpeg_compress_8u_gray(buffer, rawWidth, rawHeight, rawWidth, scale, jpegBuffer, &bufsize, 85);
 
    bp->setBlob(jpegBuffer);
    bp->setBlobLen(bufsize);
    bp->setSize(bufsize);
    bp->setFormat(".stream_jpg");
 
    return true;
}
 
/*
FROM: https://svn.csail.mit.edu/rrg_pods/jpeg-utils/
 
Name:         jpeg-utils
Maintainers:  Albert Huang <albert@csail.mit.edu>
Summary:      Wrapper functions around libjpeg to simplify JPEG compression and
              decompression with in-memory buffers.
Description:
  note: This is a simple enough library that you could just copy the .c
  and .h files in to your own programs.
 
  To use the library, link against -ljpeg-utils, or use
  pkg-config --cflags --libs jpeg-utils
 
Requirements:
  libjpeg62
 
  For faster performance, install libjpeg-turbo, an SSE-accelerated
  library that is ABI compatible with libjpeg62.
*/
 
int MJPEGEncoder::jpeg_compress_8u_gray (const uint8_t * src, uint16_t width, uint16_t height, int stride, int scale,
        uint8_t * dest,
        int * destsize, int quality)
{
    struct jpeg_compress_struct cinfo;
    struct jpeg_error_mgr jerr;
    struct jpeg_destination_mgr jdest;
    int out_size = *destsize;
 
    cinfo.err = jpeg_std_error (&jerr);
    jpeg_create_compress (&cinfo);
    jdest.next_output_byte = dest;
    jdest.free_in_buffer = out_size;
    jdest.init_destination = init_destination;
    jdest.empty_output_buffer = empty_output_buffer;
    jdest.term_destination = term_destination;
    cinfo.dest = &jdest;
 
    cinfo.image_width = width;
    cinfo.image_height = height;
#if JPEG_LIB_VERSION >= 70
    cinfo.scale_denom = scale;
#else
    INDI_UNUSED(scale);
#endif
    cinfo.input_components = 1;
    cinfo.in_color_space = JCS_GRAYSCALE;
    jpeg_set_defaults (&cinfo);
    jpeg_set_quality (&cinfo, quality, TRUE);
 
    jpeg_start_compress (&cinfo, TRUE);
    while (cinfo.next_scanline < height)
    {
        JSAMPROW row = (JSAMPROW)(src + cinfo.next_scanline * stride);
        jpeg_write_scanlines (&cinfo, &row, 1);
    }
 
    jpeg_finish_compress (&cinfo);
    *destsize = out_size - jdest.free_in_buffer;
    jpeg_destroy_compress (&cinfo);
    return 0;
}
 
int MJPEGEncoder::jpeg_compress_8u_rgb (const uint8_t * src, uint16_t width, uint16_t height, int stride, int scale,
                                        uint8_t * dest, int * destsize, int quality)
{
    struct jpeg_compress_struct cinfo;
    struct jpeg_error_mgr jerr;
    struct jpeg_destination_mgr jdest;
    int out_size = *destsize;
 
    cinfo.err = jpeg_std_error (&jerr);
    jpeg_create_compress (&cinfo);
    jdest.next_output_byte = dest;
    jdest.free_in_buffer = out_size;
    jdest.init_destination = init_destination;
    jdest.empty_output_buffer = empty_output_buffer;
    jdest.term_destination = term_destination;
    cinfo.dest = &jdest;
 
    cinfo.image_width = width;
    cinfo.image_height = height;
#if JPEG_LIB_VERSION >= 70
    cinfo.scale_denom = scale;
#else
    INDI_UNUSED(scale);
#endif
    cinfo.input_components = 3;
    cinfo.in_color_space = JCS_RGB;
    jpeg_set_defaults (&cinfo);
    jpeg_set_quality (&cinfo, quality, TRUE);
 
    jpeg_start_compress (&cinfo, TRUE);
    while (cinfo.next_scanline < height)
    {
        JSAMPROW row = (JSAMPROW)(src + cinfo.next_scanline * stride);
        jpeg_write_scanlines (&cinfo, &row, 1);
    }
    jpeg_finish_compress (&cinfo);
    *destsize = out_size - jdest.free_in_buffer;
    jpeg_destroy_compress (&cinfo);
    return 0;
}
 
}