yuvstream.C

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#include <fcntl.h>
#include <string.h>
#include <errno.h>

#include "guicast.h"
#include "pipe.h"
#include "yuvstream.h"
#include "interlacemodes.h"

YUVStream::YUVStream() { 
        y4m_init_stream_info(&stream_info);
        y4m_init_frame_info(&frame_info);
        stream_fd = -1;
        stream_pipe= 0;
        frame_count = 0;
        frame_index = 0;
}

YUVStream::~YUVStream() {               
        y4m_fini_stream_info(&stream_info);
        y4m_fini_frame_info(&frame_info);
        if (frame_index) delete frame_index;
        close_fd();
}


int YUVStream::open_read(char *path) {
        // NOTE: reading from pipes would be very difficult without temp files
        stream_fd = open(path, O_RDONLY);

        if (stream_fd < 0) {
                printf("open(%s) failed: %s\n", path, strerror(errno));
                return 1;
        }

        int result = read_header();
        if (result != Y4M_OK) {
                printf("bad YUV4MPEG2 header: %s\n", y4m_strerr(result));
                return 1;
        }

        // generate index to frame position if not done yet
        if (frame_index == 0) {
                if (make_index() != 0) {
                        return 1;
                }
        }

        return 0;
}

// NOTE: path is opened as a pipe if contains '|'
int YUVStream::open_write(char *path, char *pipe) {
        if (pipe && *pipe) {
                // skip over the '|' if present
                if (char *p = strchr(path, '|')) {
                        pipe = p + 1;
                }

                stream_pipe = new Pipe(pipe, path);
                if (stream_pipe->open_write() == 0) {
                        stream_fd = stream_pipe->fd;
                        return 0;
                }
                return 1;
        }

        stream_fd = open(path, O_CREAT|O_WRONLY|O_TRUNC, 0666);
        if (stream_fd > 0) return 0;
        
        printf("open(%s) failed: %s\n", path, strerror(errno));
        return 1;
}


void YUVStream::close_fd() {
        if (stream_pipe) {
                stream_pipe->close();
                stream_pipe = 0;
                stream_fd = -1;
        }
                
        if (stream_fd >= 0) close(stream_fd);
        stream_fd = -1;
}

int YUVStream::read_frame(uint8_t *yuv[3]) {
        int result =  y4m_read_frame(stream_fd, &stream_info, 
                                  &frame_info, yuv);
        if (result != Y4M_OK) {
                if (result != Y4M_ERR_EOF) {
                        printf("read_frame() failed: %s\n", 
                               y4m_strerr(result));
                }
                return 1;
        }

        return 0;
}

int YUVStream::read_frame_raw(uint8_t *data, long frame_size) {
#if (MJPEGTOOLS_Y4M_WRITE_FRAME_HEADER__3ARGS)
        int result = y4m_read_frame_header(stream_fd, &stream_info, &frame_info);
#else
        int result = y4m_read_frame_header(stream_fd, &frame_info);
#endif
        if (result != Y4M_OK) {
                printf("y4m_read_frame_header() failed: %s\n", 
                       y4m_strerr(result));
                return 1;
        }
        result = y4m_read(stream_fd, data, frame_size);
        if (result != Y4M_OK) {
                printf("y4m_read(%d) failed: %s\n", 
                       frame_size, y4m_strerr(result));
                return 1;
        }
        return 0;
}
                
int YUVStream::write_frame(uint8_t *yuv[3]) {
        int result = y4m_write_frame(stream_fd, &stream_info, 
                                     &frame_info, yuv);
        if (result != Y4M_OK) {
                printf("write_frame() failed: %s\n", y4m_strerr(result));
                return 1;
        }
        return 0;
}
int YUVStream::write_frame_raw(uint8_t *data, long frame_size) {
#if (MJPEGTOOLS_Y4M_WRITE_FRAME_HEADER__3ARGS)
        int result = y4m_write_frame_header(stream_fd, &stream_info, &frame_info);
#else
        int result = y4m_write_frame_header(stream_fd, &frame_info);
#endif
        if (result != Y4M_OK) {
                printf("y4m_write_frame_header() failed: %s\n", 
                       y4m_strerr(result));
                return 1;
        }
        result = y4m_write(stream_fd, data, frame_size);
        if (result != Y4M_OK) {
                printf("y4m_write(%d) failed: %s\n", 
                       frame_size, y4m_strerr(result));
                return 1;
        }
        return 0;
}               

int YUVStream::make_index() {
        off_t position;
        uint8_t *yuv[3];

        // NOTE: make_index() must be called after read_header().

        // NOTE: storing frame_index locally means it is destroyed too often.
        //       make_index() will be called 3 times per file.  If this
        //       becomes a performance problem, the index should be cached.
        //       Storing in 'asset' helps some, but still is done twice.
        if (frame_index) delete frame_index;
        frame_index = new ArrayList<off_t>;

        VFrame *frame = new VFrame(0, get_width(), get_height(), BC_YUV420P);
        yuv[0] = frame->get_y();
        yuv[1] = frame->get_u();
        yuv[2] = frame->get_v();

        // note the start of the first frame
        position = lseek(stream_fd, 0, SEEK_CUR);

        // reset the frame count
        frame_count = 0;

        while (read_frame(yuv) == 0) {
                // index is start position of each frame
                frame_index->append(position);
                position = lseek(stream_fd, 0, SEEK_CUR);
                frame_count++;
        } 

        // rewind to the start of the first frame
        lseek(stream_fd, frame_index->values[0], SEEK_SET);

        delete frame;

        return 0;
}

int YUVStream::seek_frame(int64_t frame_number) {
        if (frame_number > frame_count ||
            frame_number < 0 ||
            frame_index == 0) {
                printf("seek_frame(%d) failed (frame_count=%d)\n", 
                       frame_number, frame_count);
                return 1;
        }

        off_t position = frame_index->values[frame_number];
        if (position == 0) {
                // because of header, position should never be zero
                printf("seek_frame(%d): position was zero\n", frame_number);
        }

        if (lseek(stream_fd, position, SEEK_SET) < 0) {
                printf("lseek(%d) failed: %s\n", position, strerror(errno));
                return 1;
        }

        return 0;
}

int YUVStream::read_header() {
        int result = y4m_read_stream_header(stream_fd, &stream_info);
        if (result != Y4M_OK) {
                printf("y4m_read_stream_header() failed: %s\n", 
                       y4m_strerr(result));
                return 1;
        }
        return 0;
}
int YUVStream::write_header() {
        int result = y4m_write_stream_header(stream_fd, &stream_info);
        if (result != Y4M_OK) {
                printf("y4m_write_stream_header() failed: %s\n", 
                       y4m_strerr(result));
                return 1;
        }
        return 0;
}

int YUVStream::get_interlace() {
        return ilace_yuv4mpeg_to_bc(y4m_si_get_interlace(&stream_info));
}

void YUVStream::set_interlace(int imode) {
        y4m_si_set_interlace(&stream_info, ilace_bc_to_yuv4mpeg(imode));
}

int YUVStream::get_width() {
        return y4m_si_get_width(&stream_info);
}
void YUVStream::set_width(int width) {
        y4m_si_set_width(&stream_info, width);
}

int YUVStream::get_height() {
        return y4m_si_get_height(&stream_info);
}
void YUVStream::set_height(int height) {
        y4m_si_set_height(&stream_info, height);
}

double YUVStream::get_frame_rate() {
        y4m_ratio_t ratio = y4m_si_get_framerate(&stream_info);
        double frame_rate = (double) ratio.n / (double) ratio.d;
        return frame_rate;
}
void YUVStream::set_frame_rate(double frame_rate) {
        y4m_ratio_t ratio = mpeg_conform_framerate(frame_rate);
        y4m_si_set_framerate(&stream_info, ratio);
}

// FUTURE: these seem like a mess, possibly because I don't 
//         properly understand "display aspect" vs "pixel aspect"
double YUVStream::get_aspect_ratio() {
        y4m_ratio_t sar = y4m_si_get_sampleaspect(&stream_info);
        mpeg_aspect_code_t code = 
                mpeg_guess_mpeg_aspect_code(2, sar, 
                                            get_width(),
                                            get_height());
        y4m_ratio_t aspect_ratio =  mpeg_framerate(code);
        if (aspect_ratio.d == 0) return 0;
        return (double) aspect_ratio.n / (double) aspect_ratio.n;
}               
void YUVStream::set_aspect_ratio(double aspect_ratio) {
        y4m_ratio_t ratio;
        ratio.n = (int)(aspect_ratio * 10000);
        ratio.d = 10000;
        y4m_ratio_t sar = y4m_guess_sar(get_width(), get_height(),
                                        ratio);
        y4m_si_set_sampleaspect(&stream_info, sar);
}

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