go-rtsp/ffmpeg.c

#include "ffmpeg.h"

void ffmpeginit() {
	#if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(58, 9, 100)
	av_register_all();
	avformat_network_init();
	#endif
}

struct AVStream * stream_at(struct AVFormatContext *c, int idx) {
    if (idx >= 0 && idx < c->nb_streams)
        return c->streams[idx];
    return NULL;
}

int rtsp_encode(AVCodecContext *avctx, AVPacket *pkt, int *got_packet, AVFrame *frame)
{
    int ret;

    *got_packet = 0;

    if (!frame) {
        return -1;
    }

    ret = avcodec_send_frame(avctx, frame);
    if (ret < 0)
        return ret;

    ret = avcodec_receive_packet(avctx, pkt);
    if (!ret)
        *got_packet = 1;
    if (ret == AVERROR(EAGAIN))
        return 0;

    return ret;
}

int rtsp_avcodec_encode_wav(AVCodecContext *pCodecCtx, AVFrame *pFrame,AVPacket *packet) {
    const AVCodec *wavCodec = avcodec_find_encoder(AV_CODEC_ID_PCM_S16LE );
    int ret = -1;

    if (!wavCodec) {
        return ret;
    }

    AVCodecContext *wavContext = avcodec_alloc_context3(wavCodec);
    if (!wavContext) {
        wavCodec = NULL;
        return ret;
    }

    wavContext->bit_rate = pCodecCtx->bit_rate;
    wavContext->sample_fmt = AV_SAMPLE_FMT_S16;
    wavContext->sample_rate = pFrame->sample_rate;
    wavContext->channel_layout = pFrame->channel_layout;
    wavContext->channels = pFrame->channels;

    ret = avcodec_open2(wavContext, wavCodec, NULL);
    if (ret < 0) {
        goto error;
    }

    int gotFrame;

    ret = rtsp_encode(wavContext, packet, &gotFrame, pFrame);
    if (ret < 0) {
        goto error;
    }
    
    error:
        avcodec_close(wavContext);
        avcodec_free_context(&wavContext);
        wavCodec = NULL;
    return ret;
}

int rtsp_avcodec_encode_jpeg(AVCodecContext *pCodecCtx, AVFrame *pFrame,AVPacket *packet) {
    const AVCodec *jpegCodec = avcodec_find_encoder(AV_CODEC_ID_MJPEG);
    int ret = -1;

    if (!jpegCodec) {
        return ret;
    }

    AVCodecContext *jpegContext = avcodec_alloc_context3(jpegCodec);
    if (!jpegContext) {
        jpegCodec = NULL;
        return ret;
    }

    jpegContext->pix_fmt = AV_PIX_FMT_YUVJ420P;
    jpegContext->height = pFrame->height;
    jpegContext->width = pFrame->width;
    jpegContext->time_base= (AVRational){1,25};

    ret = avcodec_open2(jpegContext, jpegCodec, NULL);
    if (ret < 0) {
        goto error;
    }
    
    int gotFrame;

    ret = rtsp_encode(jpegContext, packet, &gotFrame, pFrame);
    if (ret < 0) {
        goto error;
    }
    
    error:
        avcodec_close(jpegContext);
        avcodec_free_context(&jpegContext);
        jpegCodec = NULL;
    return ret;
}

uint8_t *rtsp_convert(AVCodecContext *pCodecCtx,AVFrame *pFrame,AVFrame *nFrame,int *size, int format) {
    struct SwsContext *img_convert_ctx = sws_getCachedContext( NULL, pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, pFrame->width, pFrame->height, format, SWS_BICUBIC, NULL, NULL, NULL );
    nFrame->format = format;
    nFrame->width = pFrame->width;
    nFrame->height = pFrame->height;
    
    *size = av_image_get_buffer_size( format, pFrame->width, pFrame->height, 1);
    
    uint8_t *tmp_picture_buf = (uint8_t *)malloc(*size);    
    
    av_image_fill_arrays(nFrame->data, nFrame->linesize, tmp_picture_buf, format, pFrame->width, pFrame->height, 1);
    
    sws_scale(img_convert_ctx, (const uint8_t* const*)pFrame->data, pFrame->linesize, 0, nFrame->height, nFrame->data, nFrame->linesize);   
    sws_freeContext(img_convert_ctx);
    return tmp_picture_buf;
}

int rtsp_avcodec_encode_jpeg_nv12(AVCodecContext *pCodecCtx, AVFrame *pFrame,AVPacket *packet) {
    int size = 0;
    	AVFrame *nFrame = av_frame_alloc();
    uint8_t * data = rtsp_convert(pCodecCtx, pFrame, nFrame, &size, AV_PIX_FMT_YUV420P);  
    int ret = rtsp_avcodec_encode_jpeg(pCodecCtx,nFrame,packet);
    free(data);
    av_frame_free(&nFrame);
    return ret;
}


int rtsp_avcodec_encode_resample_wav(AVCodecContext *pCodecCtx,SwrContext *swr_ctx, AVFrame *pFrame,AVPacket *packet) {
    int ret = 0;
    
    AVFrame *nFrame = av_frame_alloc();
    
    nFrame->channel_layout = pFrame->channel_layout;
    nFrame->sample_rate = pFrame->sample_rate;
    nFrame->format = AV_SAMPLE_FMT_S16;

    // Without this, there is no sound at all at the output (PTS stuff I guess)
    ret = av_frame_copy_props(nFrame, pFrame);
    if (ret < 0) {
        goto error;
    }

    ret = swr_convert_frame(swr_ctx, nFrame, pFrame);
    if (ret < 0) {
        goto error;
    }

    ret = rtsp_avcodec_encode_wav(pCodecCtx,nFrame,packet); 
    if (ret < 0) {
        goto error;
    }

error:
    av_frame_free(&nFrame);

    return ret;
}