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• Codec not found while H.264 encoding using FFMPEG in iOS

  12 juin 2013, par Sukhpal Singh

  I am trying to encode video in h.264 format using FFMpeg in iOS. Actually I am receiving sample buffer from iPhone Camera and then converting it AVFrame and further from AVFrame to H.264 video. But while h.264 encoding if I use :

  codec = avcodec_find_encoder(CODEC_ID_MPEG1VIDEO);

  Then codec is found but if I use :

  codec = avcodec_find_encoder(CODEC_ID_H264);

  Then codec is nil means codec not found. Full code is as below :

  static void encode(AVFrame *picture)
  
   {
  
       AVCodec *codec;
  
       AVCodecContext *c= NULL;
  
       int i, out_size, size,  outbuf_size;
  
       uint8_t *outbuf, *picture_buf;
  
  
  
       printf("Video encoding\n");
  
  
  
       /* find the mpeg1 video encoder */
  
  
  
       //avcodec_init() ; // Also tried this but giving warning and not worked
  
       avcodec_register_all();
  
  
  
       codec = avcodec_find_encoder(CODEC_ID_H264);
  
       if (!codec) {
  
           fprintf(stderr, "codec not found\n");
  
           exit(1);
  
       }
  
  
  
       c= avcodec_alloc_context();
  
       picture= avcodec_alloc_frame();
  
  
  
       /* put sample parameters */
  
       c->bit_rate = 400000;
  
       /* resolution must be a multiple of two */
  
       c->width  = 352;
  
       c->height = 288;
  
       /* frames per second */
  
       c->time_base= (AVRational){1,25};
  
       c->gop_size = 10; /* emit one intra frame every ten frames */
  
       c->max_b_frames=1;
  
       c->pix_fmt = PIX_FMT_YUV420P;
  
  
  
       /* open it */
  
       if (avcodec_open(c, codec) < 0) {
  
           fprintf(stderr, "could not open codec\n");
  
           exit(1);
  
       }
  
  
  
           /* alloc image and output buffer */
  
       outbuf_size = 100000;
  
       outbuf = malloc(outbuf_size);
  
       size = c->width * c->height;
  
       picture_buf = malloc((size * 3) / 2); /* size for YUV 420 */
  
  
  
       out_size = avcodec_encode_video(c, outbuf, outbuf_size, picture);
  
  
  
       NSLog(@"NSdada===%@",[NSData dataWithBytes:(const void *)outbuf length:out_size]);
  
  
  
       free(picture_buf);
  
       free(outbuf);
  
  
  
       avcodec_close(c);
  
       av_free(c);
  
       av_free(picture);
  
       printf("\n");
  
   }

• Encode iOS compatible h264 audio stream with FFMPEG

  11 octobre 2014, par beamformer

  I am using FFMPEG with Python to encode a low bit rate version of videos that I import. I would like the output to be playable on several devices, including Roku and iOS. This link states that Apple supports H264 High profile, level 4.1 and MP3 audio.

  ffmpeg -preset veryslow -y -profile:v high -level 4.0 -movflags +faststart -codec:a libmp3lame -qscale:a 2 -s 1280x720 out.mp4

  The resulting videos play fine in an HTML5 browser on a computer. However, on the iPhone the video appears but the audio stream does not play. Is there an issue with the mp3 settings ?

  From ffprobe :

  [STREAM]
  
  index=1
  
  codec_name=mp3
  
  codec_long_name=MP3 (MPEG audio layer 3)
  
  profile=unknown
  
  codec_type=audio
  
  codec_time_base=1/44100
  
  codec_tag_string=mp4a
  
  codec_tag=0x6134706d
  
  sample_fmt=s16p
  
  sample_rate=44100
  
  channels=1
  
  channel_layout=mono
  
  bits_per_sample=0
  
  id=N/A
  
  r_frame_rate=0/0
  
  avg_frame_rate=0/0
  
  time_base=1/44100
  
  start_pts=-1105
  
  start_time=-0.025057
  
  duration_ts=2321489
  
  duration=52.641474
  
  bit_rate=94949
  
  max_bit_rate=N/A
  
  bits_per_raw_sample=N/A
  
  nb_frames=2016
  
  nb_read_frames=N/A
  
  nb_read_packets=N/A
  
  DISPOSITION:default=1
  
  DISPOSITION:dub=0
  
  DISPOSITION:original=0
  
  DISPOSITION:comment=0
  
  DISPOSITION:lyrics=0
  
  DISPOSITION:karaoke=0
  
  DISPOSITION:forced=0
  
  DISPOSITION:hearing_impaired=0
  
  DISPOSITION:visual_impaired=0
  
  DISPOSITION:clean_effects=0
  
  DISPOSITION:attached_pic=0
  
  TAG:language=und
  
  TAG:handler_name=SoundHandler
  
  [/STREAM]

  I tried using AAC, but did not get good results with the native FFMPEG encoder

• mp4 plays only sound but no video on ios

  5 avril 2018, par Chen

  I have a video that I get from a third party provide in my App, I want to play using react-native-video. It works fine on simulator, but on a real iphone 7 it has only sound but no video.

  After further research I found, when I try to airdrop/move via itunes the video to my iphone. It shows something like the following :

  

  I have checked the codec with ffprobe and here is the output.
  ```

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'bad.mp4':
  
    Metadata:
  
      major_brand     : mp42
  
      minor_version   : 0
  
      compatible_brands: mp42mp41
  
      creation_time   : 2018-03-28T21:30:13.000000Z
  
    Duration: 00:00:45.55, start: 0.000000, bitrate: 1373 kb/s
  
      Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080 [SAR 1:1 DAR 16:9], 1042 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
  
      Metadata:
  
        creation_time   : 2018-03-28T21:30:13.000000Z
  
        handler_name    : Alias Data Handler
  
        encoder         : AVC Coding
  
      Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 317 kb/s (default)
  
      Metadata:
  
        creation_time   : 2018-03-28T21:30:13.000000Z
  
        handler_name    : Alias Data Handler
  
  [STREAM]
  
  index=0
  
  codec_name=h264
  
  codec_long_name=H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10
  
  profile=High
  
  codec_type=video
  
  codec_time_base=1001/60000
  
  codec_tag_string=avc1
  
  codec_tag=0x31637661
  
  width=1920
  
  height=1080
  
  coded_width=1920
  
  coded_height=1080
  
  has_b_frames=1
  
  sample_aspect_ratio=1:1
  
  display_aspect_ratio=16:9
  
  pix_fmt=yuv420p
  
  level=41
  
  color_range=tv
  
  color_space=bt709
  
  color_transfer=bt709
  
  color_primaries=bt709
  
  chroma_location=left
  
  field_order=unknown
  
  timecode=N/A
  
  refs=1
  
  is_avc=true
  
  nal_length_size=4
  
  id=N/A
  
  r_frame_rate=30000/1001
  
  avg_frame_rate=30000/1001
  
  time_base=1/30000
  
  start_pts=0
  
  start_time=0.000000
  
  duration_ts=1365364
  
  duration=45.512133
  
  bit_rate=1042237
  
  max_bit_rate=N/A
  
  bits_per_raw_sample=8
  
  nb_frames=1364
  
  nb_read_frames=N/A
  
  nb_read_packets=N/A
  
  DISPOSITION:default=1
  
  DISPOSITION:dub=0
  
  DISPOSITION:original=0
  
  DISPOSITION:comment=0
  
  DISPOSITION:lyrics=0
  
  DISPOSITION:karaoke=0
  
  DISPOSITION:forced=0
  
  DISPOSITION:hearing_impaired=0
  
  DISPOSITION:visual_impaired=0
  
  DISPOSITION:clean_effects=0
  
  DISPOSITION:attached_pic=0
  
  DISPOSITION:timed_thumbnails=0
  
  TAG:creation_time=2018-03-28T21:30:13.000000Z
  
  TAG:language=eng
  
  TAG:handler_name=Alias Data Handler
  
  TAG:encoder=AVC Coding
  
  [/STREAM]
  
  [STREAM]
  
  index=1
  
  codec_name=aac
  
  codec_long_name=AAC (Advanced Audio Coding)
  
  profile=LC
  
  codec_type=audio
  
  codec_time_base=1/48000
  
  codec_tag_string=mp4a
  
  codec_tag=0x6134706d
  
  sample_fmt=fltp
  
  sample_rate=48000
  
  channels=2
  
  channel_layout=stereo
  
  bits_per_sample=0
  
  id=N/A
  
  r_frame_rate=0/0
  
  avg_frame_rate=0/0
  
  time_base=1/48000
  
  start_pts=0
  
  start_time=0.000000
  
  duration_ts=2184582
  
  duration=45.512125
  
  bit_rate=317375
  
  max_bit_rate=458625
  
  bits_per_raw_sample=N/A
  
  nb_frames=2135
  
  nb_read_frames=N/A
  
  nb_read_packets=N/A
  
  DISPOSITION:default=1
  
  DISPOSITION:dub=0
  
  DISPOSITION:original=0
  
  DISPOSITION:comment=0
  
  DISPOSITION:lyrics=0
  
  DISPOSITION:karaoke=0
  
  DISPOSITION:forced=0
  
  DISPOSITION:hearing_impaired=0
  
  DISPOSITION:visual_impaired=0
  
  DISPOSITION:clean_effects=0
  
  DISPOSITION:attached_pic=0
  
  DISPOSITION:timed_thumbnails=0
  
  TAG:creation_time=2018-03-28T21:30:13.000000Z
  
  TAG:language=eng
  
  TAG:handler_name=Alias Data Handler
  
  [/STREAM]

  Then I tried VLC on iOS the video played without problem (it has both video and sound), except at the beginning it shows a grey pixel screen.

  

  Next, what i did was using ffmpeg to re-encode the video stream via :

  ffmpeg -i bad.mp4 -c:a copy new.mp4

  After this new.mp4 plays with no problem.
  This is really confusing as the codec does not change and both videos works with no problem on my Mac.

  I have tried to play around with the b_frames, profile level on the new video to reproduce the problem but with no luck.

  I really do not want to process every video via ffmpeg after get it from the third party. Just wondering what might be the problem with the video ?