hdhomerun_video.c

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/*
 * hdhomerun_video.c
 *
 * Copyright © 2006 Silicondust USA Inc. <www.silicondust.com>.
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 * 
 * As a special exception to the GNU Lesser General Public License,
 * you may link, statically or dynamically, an application with a
 * publicly distributed version of the Library to produce an
 * executable file containing portions of the Library, and
 * distribute that executable file under terms of your choice,
 * without any of the additional requirements listed in clause 4 of
 * the GNU Lesser General Public License.
 * 
 * By "a publicly distributed version of the Library", we mean
 * either the unmodified Library as distributed by Silicondust, or a
 * modified version of the Library that is distributed under the
 * conditions defined in the GNU Lesser General Public License.
 */

#include "hdhomerun.h"

struct hdhomerun_video_sock_t {
        pthread_mutex_t lock;
        uint8_t *buffer;
        size_t buffer_size;
        volatile size_t head;
        volatile size_t tail;
        size_t advance;
        volatile bool_t terminate;
        pthread_t thread;
        int sock;
        uint32_t rtp_sequence;
        struct hdhomerun_debug_t *dbg;
        volatile uint32_t packet_count;
        volatile uint32_t transport_error_count;
        volatile uint32_t network_error_count;
        volatile uint32_t sequence_error_count;
        volatile uint32_t overflow_error_count;
        volatile uint8_t sequence[0x2000];
};

static THREAD_FUNC_PREFIX hdhomerun_video_thread_execute(void *arg);

struct hdhomerun_video_sock_t *hdhomerun_video_create(uint16_t listen_port, size_t buffer_size, struct hdhomerun_debug_t *dbg)
{
        /* Create object. */
        struct hdhomerun_video_sock_t *vs = (struct hdhomerun_video_sock_t *)calloc(1, sizeof(struct hdhomerun_video_sock_t));
        if (!vs) {
                hdhomerun_debug_printf(dbg, "hdhomerun_video_create: failed to allocate video object\n");
                return NULL;
        }

        vs->dbg = dbg;
        vs->sock = -1;
        pthread_mutex_init(&vs->lock, NULL);

        /* Reset sequence tracking. */
        hdhomerun_video_flush(vs);

        /* Buffer size. */
        vs->buffer_size = (buffer_size / VIDEO_DATA_PACKET_SIZE) * VIDEO_DATA_PACKET_SIZE;
        if (vs->buffer_size == 0) {
                hdhomerun_debug_printf(dbg, "hdhomerun_video_create: invalid buffer size (%lu bytes)\n", (unsigned long)buffer_size);
                goto error;
        }
        vs->buffer_size += VIDEO_DATA_PACKET_SIZE;

        /* Create buffer. */
        vs->buffer = (uint8_t *)malloc(vs->buffer_size);
        if (!vs->buffer) {
                hdhomerun_debug_printf(dbg, "hdhomerun_video_create: failed to allocate buffer (%lu bytes)\n", (unsigned long)vs->buffer_size);
                goto error;
        }
        
        /* Create socket. */
        vs->sock = (int)socket(AF_INET, SOCK_DGRAM, 0);
        if (vs->sock == -1) {
                hdhomerun_debug_printf(dbg, "hdhomerun_video_create: failed to allocate socket\n");
                goto error;
        }

        /* Expand socket buffer size. */
        int rx_size = 1024 * 1024;
        setsockopt(vs->sock, SOL_SOCKET, SO_RCVBUF, (char *)&rx_size, sizeof(rx_size));

        /* Set timeouts. */
        setsocktimeout(vs->sock, SOL_SOCKET, SO_SNDTIMEO, 1000);
        setsocktimeout(vs->sock, SOL_SOCKET, SO_RCVTIMEO, 1000);

        /* Bind socket. */
        struct sockaddr_in sock_addr;
        memset(&sock_addr, 0, sizeof(sock_addr));
        sock_addr.sin_family = AF_INET;
        sock_addr.sin_addr.s_addr = htonl(INADDR_ANY);
        sock_addr.sin_port = htons(listen_port);
        if (bind(vs->sock, (struct sockaddr *)&sock_addr, sizeof(sock_addr)) != 0) {
                hdhomerun_debug_printf(dbg, "hdhomerun_video_create: failed to bind socket (port %u)\n", listen_port);
                goto error;
        }

        /* Start thread. */
        if (pthread_create(&vs->thread, NULL, &hdhomerun_video_thread_execute, vs) != 0) {
                hdhomerun_debug_printf(dbg, "hdhomerun_video_create: failed to start thread\n");
                goto error;
        }

        /* Success. */
        return vs;

error:
        if (vs->sock != -1) {
                close(vs->sock);
        }
        if (vs->buffer) {
                free(vs->buffer);
        }
        free(vs);
        return NULL;
}

void hdhomerun_video_destroy(struct hdhomerun_video_sock_t *vs)
{
        vs->terminate = TRUE;
        pthread_join(vs->thread, NULL);

        close(vs->sock);
        free(vs->buffer);

        free(vs);
}

uint16_t hdhomerun_video_get_local_port(struct hdhomerun_video_sock_t *vs)
{
        struct sockaddr_in sock_addr;
        socklen_t sockaddr_size = sizeof(sock_addr);
        if (getsockname(vs->sock, (struct sockaddr*)&sock_addr, &sockaddr_size) != 0) {
                hdhomerun_debug_printf(vs->dbg, "hdhomerun_video_get_local_port: getsockname failed (%d)\n", sock_getlasterror);
                return 0;
        }

        return ntohs(sock_addr.sin_port);
}

static void hdhomerun_video_stats_ts_pkt(struct hdhomerun_video_sock_t *vs, uint8_t *ptr)
{
        uint16_t packet_identifier = ((uint16_t)(ptr[1] & 0x1F) << 8) | (uint16_t)ptr[2];
        if (packet_identifier == 0x1FFF) {
                return;
        }

        bool_t transport_error = ptr[1] >> 7;
        if (transport_error) {
                vs->transport_error_count++;
                vs->sequence[packet_identifier] = 0xFF;
                return;
        }

        uint8_t continuity_counter = ptr[3] & 0x0F;
        uint8_t previous_sequence = vs->sequence[packet_identifier];

        if (continuity_counter == ((previous_sequence + 1) & 0x0F)) {
                vs->sequence[packet_identifier] = continuity_counter;
                return;
        }
        if (previous_sequence == 0xFF) {
                vs->sequence[packet_identifier] = continuity_counter;
                return;
        }
        if (continuity_counter == previous_sequence) {
                return;
        }

        vs->sequence_error_count++;
        vs->sequence[packet_identifier] = continuity_counter;
}

static void hdhomerun_video_parse_rtp(struct hdhomerun_video_sock_t *vs, struct hdhomerun_pkt_t *pkt)
{
        pkt->pos += 2;
        uint32_t rtp_sequence = hdhomerun_pkt_read_u16(pkt);
        pkt->pos += 8;

        if (rtp_sequence != ((vs->rtp_sequence + 1) & 0xFFFF)) {
                if (vs->rtp_sequence != 0xFFFFFFFF) {
                        vs->network_error_count++;

                        /* restart pid sequence check */
                        /* can't use memset bcs sequence is volatile */
                        int i;
                        for (i = 0; i < sizeof(vs->sequence) / sizeof(uint8_t) ; i++)
                                vs->sequence[i] = 0xFF;
                }
        }

        vs->rtp_sequence = rtp_sequence;
}

static THREAD_FUNC_PREFIX hdhomerun_video_thread_execute(void *arg)
{
        struct hdhomerun_video_sock_t *vs = (struct hdhomerun_video_sock_t *)arg;
        struct hdhomerun_pkt_t pkt_inst;

        while (!vs->terminate) {
                struct hdhomerun_pkt_t *pkt = &pkt_inst;
                hdhomerun_pkt_reset(pkt);

                /* Receive. */
                int length = recv(vs->sock, (char *)pkt->end, VIDEO_RTP_DATA_PACKET_SIZE, 0);
                pkt->end += length;

                if (length == VIDEO_RTP_DATA_PACKET_SIZE) {
                        hdhomerun_video_parse_rtp(vs, pkt);
                        length = (int)(pkt->end - pkt->pos);
                }

                if (length != VIDEO_DATA_PACKET_SIZE) {
                        if (length > 0) {
                                /* Data received but not valid - ignore. */
                                continue;
                        }
                        if (sock_getlasterror_socktimeout) {
                                /* Wait for more data. */
                                continue;
                        }
                        vs->terminate = TRUE;
                        return NULL;
                }

                pthread_mutex_lock(&vs->lock);

                /* Store in ring buffer. */
                size_t head = vs->head;
                uint8_t *ptr = vs->buffer + head;
                memcpy(ptr, pkt->pos, length);

                /* Stats. */
                vs->packet_count++;
                hdhomerun_video_stats_ts_pkt(vs, ptr + TS_PACKET_SIZE * 0);
                hdhomerun_video_stats_ts_pkt(vs, ptr + TS_PACKET_SIZE * 1);
                hdhomerun_video_stats_ts_pkt(vs, ptr + TS_PACKET_SIZE * 2);
                hdhomerun_video_stats_ts_pkt(vs, ptr + TS_PACKET_SIZE * 3);
                hdhomerun_video_stats_ts_pkt(vs, ptr + TS_PACKET_SIZE * 4);
                hdhomerun_video_stats_ts_pkt(vs, ptr + TS_PACKET_SIZE * 5);
                hdhomerun_video_stats_ts_pkt(vs, ptr + TS_PACKET_SIZE * 6);

                /* Calculate new head. */
                head += length;
                if (head >= vs->buffer_size) {
                        head -= vs->buffer_size;
                }

                /* Check for buffer overflow. */
                if (head == vs->tail) {
                        vs->overflow_error_count++;
                        pthread_mutex_unlock(&vs->lock);
                        continue;
                }

                /* Atomic update. */
                vs->head = head;

                pthread_mutex_unlock(&vs->lock);
        }

        return NULL;
}

uint8_t *hdhomerun_video_recv(struct hdhomerun_video_sock_t *vs, size_t max_size, size_t *pactual_size)
{
        pthread_mutex_lock(&vs->lock);

        size_t head = vs->head;
        size_t tail = vs->tail;

        if (vs->advance > 0) {
                tail += vs->advance;
                if (tail >= vs->buffer_size) {
                        tail -= vs->buffer_size;
                }
        
                /* Atomic update. */
                vs->tail = tail;
        }

        if (head == tail) {
                vs->advance = 0;
                *pactual_size = 0;
                pthread_mutex_unlock(&vs->lock);
                return NULL;
        }

        size_t size = (max_size / VIDEO_DATA_PACKET_SIZE) * VIDEO_DATA_PACKET_SIZE;
        if (size == 0) {
                vs->advance = 0;
                *pactual_size = 0;
                pthread_mutex_unlock(&vs->lock);
                return NULL;
        }

        size_t avail;
        if (head > tail) {
                avail = head - tail;
        } else {
                avail = vs->buffer_size - tail;
        }
        if (size > avail) {
                size = avail;
        }
        vs->advance = size;
        *pactual_size = size;
        uint8_t *result = vs->buffer + tail;

        pthread_mutex_unlock(&vs->lock);
        return result;
}

void hdhomerun_video_flush(struct hdhomerun_video_sock_t *vs)
{
        pthread_mutex_lock(&vs->lock);

        vs->tail = vs->head;
        vs->advance = 0;

        /* can't use memset bcs sequence is volatile */
        int i;
        for (i = 0; i < sizeof(vs->sequence) / sizeof(uint8_t) ; i++)
                vs->sequence[i] = 0xFF;

        vs->rtp_sequence = 0xFFFFFFFF;

        vs->packet_count = 0;
        vs->transport_error_count = 0;
        vs->network_error_count = 0;
        vs->sequence_error_count = 0;
        vs->overflow_error_count = 0;

        pthread_mutex_unlock(&vs->lock);
}

void hdhomerun_video_debug_print_stats(struct hdhomerun_video_sock_t *vs)
{
        struct hdhomerun_video_stats_t stats;
        hdhomerun_video_get_stats(vs, &stats);

        hdhomerun_debug_printf(vs->dbg, "video sock: pkt=%ld net=%ld te=%ld miss=%ld drop=%ld\n",
                stats.packet_count, stats.network_error_count,
                stats.transport_error_count, stats.sequence_error_count,
                stats.overflow_error_count
        );
}

void hdhomerun_video_get_stats(struct hdhomerun_video_sock_t *vs, struct hdhomerun_video_stats_t *stats)
{
        memset(stats, 0, sizeof(struct hdhomerun_video_stats_t));

        pthread_mutex_lock(&vs->lock);

        stats->packet_count = vs->packet_count;
        stats->network_error_count = vs->network_error_count;
        stats->transport_error_count = vs->transport_error_count;
        stats->sequence_error_count = vs->sequence_error_count;
        stats->overflow_error_count = vs->overflow_error_count;

        pthread_mutex_unlock(&vs->lock);
}

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