rtsp.c: new example

/*

 * Copyright (c) 2011, Jim Hollinger

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *   * Redistributions of source code must retain the above copyright

 *     notice, this list of conditions and the following disclaimer.

 *   * Redistributions in binary form must reproduce the above copyright

 *     notice, this list of conditions and the following disclaimer in the

 *     documentation and/or other materials provided with the distribution.

 *   * Neither the name of Jim Hollinger nor the names of its contributors

 *     may be used to endorse or promote products derived from this

 *     software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 *

 */

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#if defined (WIN32)

#  include <conio.h>  // _getch()

#else

#  include <termios.h>

#  include <unistd.h>

  int _getch(void) {

    struct termios oldt, newt;

    tcgetattr( STDIN_FILENO, &oldt );

    newt = oldt;

    newt.c_lflag &= ~( ICANON | ECHO );

    tcsetattr( STDIN_FILENO, TCSANOW, &newt );

    int ch = getchar();

    tcsetattr( STDIN_FILENO, TCSANOW, &oldt );

    return ch;

  }

#endif

#include <curl/curl.h>

#define VERSION_STR  "V1.0"

// error handling macros

#define my_curl_easy_setopt(A, B, C) \

  if ((res = curl_easy_setopt((A), (B), (C))) != CURLE_OK) \

    fprintf(stderr, "curl_easy_setopt(%s, %s, %s) failed: %d\n", #A, #B, #C, res);

#define my_curl_easy_perform(A) \

  if ((res = curl_easy_perform((A))) != CURLE_OK) \

    fprintf(stderr, "curl_easy_perform(%s) failed: %d\n", #A, res);

// send RTSP OPTIONS request

void rtsp_options(CURL *curl, const char *uri) {

    CURLcode res = CURLE_OK;

    printf("\nRTSP: OPTIONS %s\n", uri);

    my_curl_easy_setopt(curl, CURLOPT_RTSP_STREAM_URI, uri);

    my_curl_easy_setopt(curl, CURLOPT_RTSP_REQUEST, CURL_RTSPREQ_OPTIONS);

    my_curl_easy_perform(curl);

}

// send RTSP DESCRIBE request and write sdp response to a file

void rtsp_describe(CURL *curl, const char *uri, const char *sdp_filename) {

    CURLcode res = CURLE_OK;

    printf("\nRTSP: DESCRIBE %s\n", uri);

    FILE *sdp_fp = fopen(sdp_filename, "wt");

    if (sdp_fp == NULL) {

        fprintf(stderr, "Could not open '%s' for writing\n", sdp_filename);

        sdp_fp = stdout;

    } else {

        printf("Writing SDP to '%s'\n", sdp_filename);

    }

    my_curl_easy_setopt(curl, CURLOPT_WRITEDATA, sdp_fp);

    my_curl_easy_setopt(curl, CURLOPT_RTSP_REQUEST, CURL_RTSPREQ_DESCRIBE);

    my_curl_easy_perform(curl);

    my_curl_easy_setopt(curl, CURLOPT_WRITEDATA, stdout);

    if (sdp_fp != stdout) {

        fclose(sdp_fp);

    }

}

// send RTSP SETUP request

void rtsp_setup(CURL *curl, const char *uri, const char *transport) {

    CURLcode res = CURLE_OK;

    printf("\nRTSP: SETUP %s\n", uri);

    printf("      TRANSPORT %s\n", transport);

    my_curl_easy_setopt(curl, CURLOPT_RTSP_STREAM_URI, uri);

    my_curl_easy_setopt(curl, CURLOPT_RTSP_TRANSPORT, transport);

    my_curl_easy_setopt(curl, CURLOPT_RTSP_REQUEST, CURL_RTSPREQ_SETUP);

    my_curl_easy_perform(curl);

}

// send RTSP PLAY request

void rtsp_play(CURL *curl, const char *uri, const char *range) {

    CURLcode res = CURLE_OK;

    printf("\nRTSP: PLAY %s\n", uri);

    my_curl_easy_setopt(curl, CURLOPT_RTSP_STREAM_URI, uri);

    my_curl_easy_setopt(curl, CURLOPT_RANGE, range);

    my_curl_easy_setopt(curl, CURLOPT_RTSP_REQUEST, CURL_RTSPREQ_PLAY);

    my_curl_easy_perform(curl);

}

// send RTSP TEARDOWN request

void rtsp_teardown(CURL *curl, const char *uri) {

    CURLcode res = CURLE_OK;

    printf("\nRTSP: TEARDOWN %s\n", uri);

    my_curl_easy_setopt(curl, CURLOPT_RTSP_REQUEST, CURL_RTSPREQ_TEARDOWN);

    my_curl_easy_perform(curl);

}

// convert url into an sdp filename

void get_sdp_filename(const char *url, char *sdp_filename) {

    strcpy(sdp_filename, "video.sdp");

    const char *s = strrchr(url, '/');

    if (s != NULL) {

        s++;

        if (s[0] != '\0') {

            sprintf(sdp_filename, "%s.sdp", s);

        }

    }

}

// scan sdp file for media control attribute

void get_media_control_attribute(const char *sdp_filename, char *control) {

    control[0] = '\0';

    int max_len = 256;

    char *s = new char[max_len];

    FILE *sdp_fp = fopen(sdp_filename, "rt");

    if (sdp_fp != NULL) {

        while (fgets(s, max_len - 2, sdp_fp) != NULL) {

            sscanf(s, " a = control: %s", control);

        }

        fclose(sdp_fp);

    }

    delete []s;

}

// main app

int main(int argc, char * const argv[]) {

    const char *transport = "RTP/AVP;unicast;client_port=1234-1235";  // UDP		

//    const char *transport = "RTP/AVP/TCP;unicast;client_port=1234-1235";  // TCP

    const char *range = "0.000-";

    int rc = EXIT_SUCCESS;

    printf("\nRTSP request %s\n", VERSION_STR);

    printf("    Project web site: http://code.google.com/p/rtsprequest/\n");

    printf("    Requires cURL V7.20 or greater\n\n");

    // check command line

    char *basename = NULL;

    if ((argc != 2) && (argc != 3)) {

        basename = strrchr(argv[0], '/');

        if (basename == NULL) {

            basename = strrchr(argv[0], '\\');

        }

        if (basename == NULL) {

            basename = argv[0];

        } else {

            basename++;

        }

        printf("Usage:   %s url [transport]\n", basename);

        printf("         url of video server\n");

        printf("         transport (optional) specifier for media stream protocol\n");

        printf("         default transport: %s\n", transport);

        printf("Example: %s rtsp://192.168.0.2/media/video1\n\n", basename);

        rc = EXIT_FAILURE;

    } else {

        const char *url = argv[1];

        char *uri = new char[strlen(url) + 32];

        char *sdp_filename = new char[strlen(url) + 32];

        char *control = new char[strlen(url) + 32];

        get_sdp_filename(url, sdp_filename);

        if (argc == 3) {

            transport = argv[2];

        }

        // initialize curl

        CURLcode res = CURLE_OK;

        res = curl_global_init(CURL_GLOBAL_ALL);

        if (res == CURLE_OK) {

            curl_version_info_data *data = curl_version_info(CURLVERSION_NOW);

            fprintf(stderr, "    cURL V%s loaded\n", data->version);

            // initialize this curl session

            CURL *curl = curl_easy_init();

            if (curl != NULL) {

                my_curl_easy_setopt(curl, CURLOPT_VERBOSE, 0L);

                my_curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 1L);

                my_curl_easy_setopt(curl, CURLOPT_WRITEHEADER, stdout);

                my_curl_easy_setopt(curl, CURLOPT_URL, url);

                // request server options

                sprintf(uri, "%s", url);

                rtsp_options(curl, uri);

                // request session description and write response to sdp file

                rtsp_describe(curl, uri, sdp_filename);

                // get media control attribute from sdp file

                get_media_control_attribute(sdp_filename, control);

                // setup media stream

                sprintf(uri, "%s/%s", url, control);

                rtsp_setup(curl, uri, transport);

                // start playing media stream

                sprintf(uri, "%s/", url);

                rtsp_play(curl, uri, range);

                printf("Playing video, press any key to stop ...");

                _getch();

                printf("\n");

                // teardown session

                rtsp_teardown(curl, uri);

                // cleanup

                curl_easy_cleanup(curl);

                curl = NULL;

            } else {

                fprintf(stderr, "curl_easy_init() failed\n");

            }

            curl_global_cleanup();

        } else {

            fprintf(stderr, "curl_global_init(%s) failed\n", "CURL_GLOBAL_ALL", res);

        }

        delete []control;

        delete []sdp_filename;

        delete []uri;

    }

    return rc;

}