Use this code Jimmy Bhaktha....
Code for the issue and getting rgb frames from raw H.264 Frame is as follows:
avcodec_register_all(); av_register_all(); avformat_network_init();
AVDictionary *options = NULL;
AVFormatContext *refrenceFormatCtx = NULL;
AVInputFormat *fmts = av_find_input_format("h264");
char errorsdef[100];
AVCodecContext* codec_ctx = NULL;
int video_stream_index = 0;
SwsContext *img_convert_ctx = NULL;
AVFrame* picture_yuv = NULL;
AVFrame* picture_rgb = NULL;
uint8_t* picture_buffer_rgb;
uint8_t *rgb_image_data;
int sizeofrgbpicture = 0;
int initialize_rgb_requirements=1;
picture_yuv = av_frame_alloc();
av_dict_set(&options, "flags", "bicubic", 0);
av_opt_set(refrenceFormatCtx,"f","h264", AV_OPT_SEARCH_CHILDREN);
av_opt_set(refrenceFormatCtx,"codec:v","h264",AV_OPT_SEARCH_CHILDREN);
av_opt_set(refrenceFormatCtx,"probesize","32M", AV_OPT_SEARCH_CHILDREN); //
Open video file int err =
avformat_open_input(&refrenceFormatCtx,"tcp://192.168.42.129:2226", fmts,
&options);
if (!options) {
int dict_count = av_dict_count(options);
qDebug() << "dict_count " << dict_count;
}
av_strerror(err,errorsdef,100);
qDebug() << "OPening Stream error: "<< err << " "<< errorsdef;
if (refrenceFormatCtx!=NULL){
err = avformat_find_stream_info(refrenceFormatCtx, &options);
if( err< 0){
av_strerror(err,errorsdef,100);
qDebug() << "Not able to find stream: "<< err << " "<< errorsdef;
}
}else{
qDebug() << "referencecontext null";
exit(1);
} //search video stream
for (int i = 0; i < (int)refrenceFormatCtx->nb_streams; i++)
{
AVStream* s = refrenceFormatCtx->streams[i];
if (s->codec == NULL){
continue;
}
codec_ctx = (s->codec);
if (codec_ctx->codec_type == AVMEDIA_TYPE_VIDEO){
video_stream_index = i;
}
}
AVPacket packet; av_init_packet(&packet); //open output file
AVFormatContext* output_ctx = avformat_alloc_context();
AVStream* stream = NULL; //start reading packets from stream and emit data
pointer to slot
av_read_play(refrenceFormatCtx); //play RTSP
avcodec_copy_context(codec_ctx,
refrenceFormatCtx->streams[video_stream_index]->codec);
if (avcodec_open2(codec_ctx, avcodec_find_decoder(AV_CODEC_ID_H264), NULL) < 0){
qDebug() << "avcodec_open2 null";
} while (av_read_frame(refrenceFormatCtx, &packet) >= 0) {
if (packet.stream_index == video_stream_index) { //packet is video
if (stream == NULL) { //create stream in file
stream = avformat_new_stream(output_ctx,
refrenceFormatCtx->streams[video_stream_index]->codec->codec);
avcodec_copy_context(stream->codec,
refrenceFormatCtx->streams[video_stream_index]->codec);
stream->sample_aspect_ratio =
refrenceFormatCtx->streams[video_stream_index]->codec->sample_aspect_ratio;
} int check = 0; packet.stream_index = stream->id; int result = av
codec_decode_video2(codec_ctx, picture_yuv, &check, &packet);
av_free_packet(&packet);
av_packet_unref(&packet);
if(result <= 0 || check == 0){
continue;
}
if(initialize_rgb_requirements) {
sizeofrgbpicture = avpicture_get_size(AV_PIX_FMT_RGB24, codec_ctx->width,
codec_ctx->height);
picture_rgb = av_frame_alloc();
picture_buffer_rgb = (uint8_t*) (av_malloc(sizeofrgbpicture));
avpicture_fill((AVPicture *) picture_rgb, picture_buffer_rgb, AV_PIX_FMT_RGB24,
codec_ctx->width, codec_ctx->height);
img_convert_ctx = sws_getContext(codec_ctx->width, codec_ctx->height,
AV_PIX_FMT_YUV420P, codec_ctx->width, codec_ctx->height, AV_PIX_FMT_RGB24,
SWS_BICUBIC, NULL, NULL, NULL); initialize_rgb_requirements=0;
}
int height = 0;
if(picture_yuv->data != NULL) { height = sws_scale(img_convert_ctx,
((AVPicture*)picture_yuv)->data, ((AVPicture*)picture_yuv)->linesize, 0,
codec_ctx->height,
((AVPicture*)picture_rgb)->data,((AVPicture*)picture_rgb)->linesize);
}
rgb_image_data = (uint8_t *)malloc(sizeofrgbpicture * sizeof(uint8_t));
int ret = avpicture_layout((AVPicture *)picture_rgb, AV_PIX_FMT_RGB24,
codec_ctx->width, codec_ctx->height, rgb_image_data, sizeofrgbpicture);
emit imageQueued(rgb_image_data, codec_ctx->width,codec_ctx->height);
}
msleep(1);
}
av_freep(picture_buffer_rgb);
av_frame_free(&picture_rgb);
avio_close(output_ctx->pb);
avformat_free_context(output_ctx); avformat_close_input(&refrenceFormatCtx);
we have to tell ffmpeg that the format is h264. For that I have used
AVInputFormat, to set other options like video codec and probesize, I have used
av_op_set(). To set the default flags in ffmpeg, I have used av_dict_set(). I
have emitted the data pointer to my required slot. If any one wants to create a
file from it, then it can generate .ppm file by writing this pointer into file.
Thanks & Regards,
Niraj Gandha
Trainee Engineer | PES
Tel: 7016116093 | Cell: 9408781216 | Ext.: 3318
Product Engineering Services
Software | System | Silicon | Mechanical
<http://www.einfochips.com/>
www.einfochips.com
|
[email protected]<mailto:[email protected]>
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From: Libav-user <[email protected]> on behalf of Jimmy Bhaktha
<[email protected]>
Sent: Tuesday, September 25, 2018 12:55:49 AM
To: [email protected]
Subject: [External] [Libav-user] (no subject)
CAUTION: This email originated from outside of the organization. Do not click
links or open attachments unless you recognize the sender and know the content
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Hi
I am working on an application based on FFMPEG version 3.4.2 where the RTSP
packets from the camera are captured and store using python. The decoder
application is run later. The application receives a byte array which is the
actual packet. The goal is to decode the received packet and convert it to RGB
from YUV.
When I feed it packets I see the following output
Creating the codec h264
Creating the codec context
[h264 @ 0x557a3846d880] nal_unit_type: 7, nal_ref_idc: 3
[h264 @ 0x557a3846d880] nal_unit_type: 8, nal_ref_idc: 3
[h264 @ 0x557a3846d880] nal_unit_type: 5, nal_ref_idc: 3
[h264 @ 0x557a3846d880] Reinit context to 2688x1520, pix_fmt: yuvj420p
avcodec_send_packet=0
avcodec_receive_frame=0, pCodecCtx->frame_number=1
[swscaler @ 0x557a385fdb20] bad src image pointers
avcodec_send_packet=0
avcodec_receive_frame=0, pCodecCtx->frame_number=2
[swscaler @ 0x557a385fdb20] bad src image pointers
I was wondering why the swscaler is complaining about bad src images.
Here is the sequence of calls in my code
1. av_packet_alloc() and av_packet_init()
- copy the encoded image to packet->data (I extend it by
AV_INPUT_BUFFER_PADDING_SIZE and set the memory to zero
2. av_register_all();
3. Create the codec and Codec Context for h264 and open it.
- I Copy the extra data from the encoded frame to this context.
4. Allocate the memory for the frames (YUV and RGB)
5. First time using the coded I call decode - I see the codec context now has
the correct values for height and width.
- For decoding I use the avcodec_send_packet and check in a while loop for
avcodec_receive_frame() I see the number of decoded frames in the codec context
goes up (pCodecCtx->frame_number)
6. Use this codec context to set up the sws_context
7. Use the sws_context and the YUV frame decoded to get the RGB frame.
--
Jimmy Bhaktha
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