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来源：互联网发布：html用外接引入js 编辑：程序博客网时间：2024/06/04 19:57
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#include <libavcodec/avcodec.h>#include <libavformat/avformat.h>#include <libavutil/timestamp.h>#define STREAM_FRAME_RATE 25 /* 25 images/s */#define STREAM_PIX_FMT    AV_PIX_FMT_YUV420P /* default pix_fmt */static AVFormatContext *ifmt_ctx;static AVFormatContext *ofmt_ctx;typedef struct StreamContext {    AVCodecContext *dec_ctx;    AVCodecContext *enc_ctx;} StreamContext;static StreamContext *stream_ctx;typedef struct OutputStream {    AVStream *st;    AVCodecContext *enc;    /* pts of the next frame that will be generated */    int64_t next_pts;    AVFrame *frame;} OutputStream;static OutputStream ost = {0};static int video_idx;static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt){    AVRational *time_base = &fmt_ctx->streams[pkt->stream_index]->time_base;    printf("pts:%s pts_time:%s dts:%s dts_time:%s duration:%s duration_time:%s stream_index:%d\n",           av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, time_base),           av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, time_base),           av_ts2str(pkt->duration), av_ts2timestr(pkt->duration, time_base),           pkt->stream_index);}static int write_frame(AVFormatContext *fmt_ctx, const AVRational *time_base, AVStream *st, AVPacket *pkt){    /* rescale output packet timestamp values from codec to stream timebase */    av_packet_rescale_ts(pkt, *time_base, st->time_base);    pkt->stream_index = st->index;    /* Write the compressed frame to the media file. */    log_packet(fmt_ctx, pkt);    return av_interleaved_write_frame(fmt_ctx, pkt);}static int open_input_file(const char *src_filename){    int ret;    unsigned int i;    ifmt_ctx = NULL;    if ((ret = avformat_open_input(&ifmt_ctx, src_filename, NULL, NULL)) < 0) {        av_log(NULL, AV_LOG_ERROR, "Cannot open input file\n");        return ret;    }    if ((ret = avformat_find_stream_info(ifmt_ctx, NULL)) < 0) {        av_log(NULL, AV_LOG_ERROR, "Cannot find stream information\n");        return ret;    }    stream_ctx = av_mallocz_array(ifmt_ctx->nb_streams, sizeof(*stream_ctx));    if (!stream_ctx)        return AVERROR(ENOMEM);    for (i = 0; i < ifmt_ctx->nb_streams; i++) {        if (ifmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) {            video_idx = i;            AVStream *stream = ifmt_ctx->streams[i];            AVCodec *dec = avcodec_find_decoder(stream->codecpar->codec_id);            AVCodecContext *codec_ctx;            if (!dec) {                av_log(NULL, AV_LOG_ERROR, "Failed to find decoder for stream #%u\n", i);                return AVERROR_DECODER_NOT_FOUND;            }            codec_ctx = avcodec_alloc_context3(dec);            if (!codec_ctx) {                av_log(NULL, AV_LOG_ERROR, "Failed to allocate the decoder context for stream #%u\n", i);                return AVERROR(ENOMEM);            }            ret = avcodec_parameters_to_context(codec_ctx, stream->codecpar);            codec_ctx->framerate = av_guess_frame_rate(ifmt_ctx, stream, NULL);            /* Open decoder */            ret = avcodec_open2(codec_ctx, dec, NULL);            if (ret < 0) {                av_log(NULL, AV_LOG_ERROR, "Failed to open decoder for stream #%u\n", i);                return ret;            }            stream_ctx[0].dec_ctx = codec_ctx;        }    }    av_dump_format(ifmt_ctx, 0, src_filename, 0);    return 0;}static AVFrame *alloc_picture(enum AVPixelFormat pix_fmt, int width, int height){    AVFrame *picture;    int ret;    picture = av_frame_alloc();    if (!picture)        return NULL;    picture->format = pix_fmt;    picture->width  = width;    picture->height = height;    /* allocate the buffers for the frame data */    ret = av_frame_get_buffer(picture, 32);    if (ret < 0) {        fprintf(stderr, "Could not allocate frame data.\n");        exit(1);    }    return picture;}static void fill_yuv_image(AVFrame *pict, int frame_index,                           int width, int height){    int x, y, i;    i = frame_index;    /* Y */    for (y = 0; y < height; y++)        for (x = 0; x < width; x++)            pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3;    /* Cb and Cr */    for (y = 0; y < height / 2; y++) {        for (x = 0; x < width / 2; x++) {            pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2;            pict->data[2][y * pict->linesize[2] + x] = 64 + x + i * 5;        }    }}static int open_output_file(const char *filename){    AVStream *out_stream;    AVStream *in_stream;    AVCodecContext *dec_ctx, *enc_ctx;    AVCodec *encoder;    int ret;    unsigned int i;    ofmt_ctx = NULL;    avformat_alloc_output_context2(&ofmt_ctx, NULL, "flv", filename);    if (!ofmt_ctx) {        av_log(NULL, AV_LOG_ERROR, "Could not create output context\n");        return AVERROR_UNKNOWN;    }    for (i = 0; i < ifmt_ctx->nb_streams; i++) {        out_stream = avformat_new_stream(ofmt_ctx, NULL);        if (!out_stream) {            av_log(NULL, AV_LOG_ERROR, "Failed allocating output stream\n");            return AVERROR_UNKNOWN;        }        in_stream = ifmt_ctx->streams[i];        if (i == video_idx) {            ost.st = out_stream;            dec_ctx = stream_ctx[0].dec_ctx;            encoder = avcodec_find_encoder(dec_ctx->codec_id);            if (!encoder) {                av_log(NULL, AV_LOG_FATAL, "Necessary encoder not found\n");                return AVERROR_INVALIDDATA;            }            enc_ctx = avcodec_alloc_context3(encoder);            if (!enc_ctx) {                av_log(NULL, AV_LOG_FATAL, "Failed to allocate the encoder context\n");                return AVERROR(ENOMEM);            }            ost.enc = enc_ctx;            stream_ctx[0].enc_ctx = enc_ctx;            enc_ctx->codec_id = dec_ctx->codec_id;            enc_ctx->bit_rate = 400000;            enc_ctx->width    = 352;            enc_ctx->height   = 288;            out_stream->time_base = (AVRational){ 1, STREAM_FRAME_RATE };            enc_ctx->time_base       = ost.st->time_base;            enc_ctx->gop_size      = 12; /* emit one intra frame every twelve frames at most */            enc_ctx->pix_fmt       = STREAM_PIX_FMT;            ret = avcodec_open2(enc_ctx, encoder, NULL);            if (ret < 0) {                av_log(NULL, AV_LOG_ERROR, "Cannot open video encoder for stream #%u\n", i);                return ret;            }            ost.frame = alloc_picture(enc_ctx->pix_fmt, enc_ctx->width, enc_ctx->height);            if (!ost.frame) {                printf("Could not allocate video frame");                exit(1);            }            ret = avcodec_parameters_from_context(out_stream->codecpar, enc_ctx);            if (ret < 0) {                av_log(NULL, AV_LOG_ERROR, "Failed to copy encoder parameters to output stream #%u\n", i);                return ret;            }        } else {            ret = avcodec_parameters_copy(out_stream->codecpar, in_stream->codecpar);            if (ret < 0) {                printf( "Failed to copy context from input to output stream codec context\n");                return ret;            }            out_stream->time_base = in_stream->time_base;        }        // if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)            /* out_stream->codec->flags |= AV_CODEC_FLAG_GLOBAL_HEADER; */    }    av_dump_format(ofmt_ctx, 0, filename, 1);    if (!(ofmt_ctx->oformat->flags & AVFMT_NOFILE)) {        ret = avio_open(&ofmt_ctx->pb, filename, AVIO_FLAG_WRITE);        if (ret < 0) {            av_log(NULL, AV_LOG_ERROR, "Could not open output file '%s'", filename);            return ret;        }    }    /* init muxer, write output file header */    ret = avformat_write_header(ofmt_ctx, NULL);    if (ret < 0) {        av_log(NULL, AV_LOG_ERROR, "Error occurred when opening output file\n");        return ret;    }    return 0;}static AVFrame *get_video_frame(OutputStream *ost){    AVCodecContext *c = ost->enc;    if (av_frame_make_writable(ost->frame) < 0)        exit(1);    fill_yuv_image(ost->frame, ost->next_pts, c->width, c->height);    ost->frame->pts = ost->next_pts++;    return ost->frame;}static int filter_encode_write_frame(AVFrame *frame, unsigned int stream_index){    int ret;    AVFrame *filt_frame;    AVCodecContext *c;    int got_packet = 0;    AVPacket pkt = { 0 };    av_log(NULL, AV_LOG_INFO, "Pushing decoded frame to filters\n");    c = ost.enc;    filt_frame = get_video_frame(&ost);    av_init_packet(&pkt);    /* encode the image */    ret = avcodec_encode_video2(c, &pkt, filt_frame, &got_packet);    if (ret < 0) {        fprintf(stderr, "Error encoding video frame: %s\n", av_err2str(ret));        exit(1);    }    if (got_packet) {        ret = write_frame(ofmt_ctx, &c->time_base, ost.st, &pkt);    } else {        ret = 0;    }    if (ret < 0) {        fprintf(stderr, "Error while writing video frame: %s\n", av_err2str(ret));        exit(1);    }    return ret;}int main(int argc, char *argv[]){    const char * src_filename = "rtmp://live.hkstv.hk.lxdns.com/live/hks";    /* const char * src_filename = "test.flv"; */    /* const char * dst_filename = "rtmp://localhost/publishlive/livestream"; */    const char * dst_filename = "demo.flv";    int frame_count = 0;    int ret, got_frame;    AVPacket packet = { .data = NULL, .size = 0 };    AVFrame *frame = NULL;    enum AVMediaType type;    // Register    av_register_all();    // Network    avformat_network_init();    if ((ret = open_input_file(src_filename)) < 0)        goto end;    if ((ret = open_output_file(dst_filename)) < 0)        goto end;    while (1) {        if(ret = av_read_frame(ifmt_ctx, &packet) < 0)            break;        if(packet.stream_index == video_idx){            printf("Send %8d video frames to output URL\n",frame_count);            frame_count++;            frame = av_frame_alloc();            if (!frame) {                ret = AVERROR(ENOMEM);                break;            }            ret = avcodec_decode_video2(stream_ctx[0].dec_ctx, frame,                    &got_frame, &packet);            if (ret < 0) {                av_frame_free(&frame);                av_log(NULL, AV_LOG_ERROR, "Decoding failed\n");                break;            }            if (got_frame) {                frame->pts = av_frame_get_best_effort_timestamp(frame);                ret = filter_encode_write_frame(frame, video_idx);                av_frame_free(&frame);                if (ret < 0)                    goto end;            } else {                av_frame_free(&frame);            }        } else {            log_packet(ofmt_ctx, &packet);            ret = av_interleaved_write_frame(ofmt_ctx, &packet);            if (ret < 0) {                printf( "Error muxing packet\n");                break;            }        }        av_packet_unref(&packet);    }    av_write_trailer(ofmt_ctx);end:    avformat_close_input(&ifmt_ctx);    if (ofmt_ctx && !(ofmt_ctx->oformat->flags & AVFMT_NOFILE))        avio_close(ofmt_ctx->pb);    avformat_free_context(ofmt_ctx);    if (ret < 0 && ret != AVERROR_EOF) {        printf( "Error occurred.\n");        return -1;    }    return 0;}
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