Recherche avancée
Médias (29)
-
#7 Ambience
16 octobre 2011, par
Mis à jour : Juin 2015
Langue : English
Type : Audio
-
#6 Teaser Music
16 octobre 2011, par
Mis à jour : Février 2013
Langue : English
Type : Audio
-
#5 End Title
16 octobre 2011, par
Mis à jour : Février 2013
Langue : English
Type : Audio
-
#3 The Safest Place
16 octobre 2011, par
Mis à jour : Février 2013
Langue : English
Type : Audio
-
#4 Emo Creates
15 octobre 2011, par
Mis à jour : Février 2013
Langue : English
Type : Audio
-
#2 Typewriter Dance
15 octobre 2011, par
Mis à jour : Février 2013
Langue : English
Type : Audio
Autres articles (78)
-
Dépôt de média et thèmes par FTP
31 mai 2013, parL’outil MédiaSPIP traite aussi les média transférés par la voie FTP. Si vous préférez déposer par cette voie, récupérez les identifiants d’accès vers votre site MédiaSPIP et utilisez votre client FTP favori.
Vous trouverez dès le départ les dossiers suivants dans votre espace FTP : config/ : dossier de configuration du site IMG/ : dossier des média déjà traités et en ligne sur le site local/ : répertoire cache du site web themes/ : les thèmes ou les feuilles de style personnalisées tmp/ : dossier de travail (...) -
Qualité du média après traitement
21 juin 2013, parLe bon réglage du logiciel qui traite les média est important pour un équilibre entre les partis ( bande passante de l’hébergeur, qualité du média pour le rédacteur et le visiteur, accessibilité pour le visiteur ). Comment régler la qualité de son média ?
Plus la qualité du média est importante, plus la bande passante sera utilisée. Le visiteur avec une connexion internet à petit débit devra attendre plus longtemps. Inversement plus, la qualité du média est pauvre et donc le média devient dégradé voire (...) -
Le plugin : Podcasts.
14 juillet 2010, parLe problème du podcasting est à nouveau un problème révélateur de la normalisation des transports de données sur Internet.
Deux formats intéressants existent : Celui développé par Apple, très axé sur l’utilisation d’iTunes dont la SPEC est ici ; Le format "Media RSS Module" qui est plus "libre" notamment soutenu par Yahoo et le logiciel Miro ;
Types de fichiers supportés dans les flux
Le format d’Apple n’autorise que les formats suivants dans ses flux : .mp3 audio/mpeg .m4a audio/x-m4a .mp4 (...)
Sur d’autres sites (6466)
-
Piping yt_dlp to FFMPEG using python : ffmpeg failing to recognize video data from pipe
19 juillet 2024, par ThePrinceI am trying to pipe the output of yt_dlp into a pipe used by ffmpeg which then outputs. :


def pipe_function(url):

ydl_command = [
 'yt-dlp', '-f', 'bestvideo+bestaudio', '--quiet', '--no-warnings', '-o', '-', url
]


ffmpeg_command = [
 'ffmpeg', '-v', 'debug', '-i', '-', '-c', 'copy', 'output.mp4'
]


# Start yt-dlp process
ydl_process = subprocess.Popen(
 ydl_command,
 stdout=subprocess.PIPE,
 stderr=subprocess.PIPE
)


# Start ffmpeg process and pipe output from yt-dlp to ffmpeg
ffmpeg_process = subprocess.Popen(
 ffmpeg_command,
 stdin=ydl_process.stdout,
 stdout=subprocess.PIPE,
 stderr=subprocess.PIPE
)



ydl_stdout, ydl_stderr = ydl_process.communicate()


try:
 print(ydl_stdout[:100].decode('utf-8'))
except UnicodeDecodeError:
 print(ydl_stdout[:100].decode('latin-1', errors='ignore'))

ffmpeg_stdout, ffmpeg_stderr = ffmpeg_process.communicate()


if ydl_stderr:
 try:
 print("error in yt-dlp: ", ydl_stderr.decode('utf-8'))
 except UnicodeDecodeError:
 print("decode error in yt-dlp: ", ydl_stderr)

if ffmpeg_stderr:
 try:
 print("error in ffmpeg: ", ffmpeg_stderr.decode('utf-8'))
 except UnicodeDecodeError:
 print("decode error in ffmpeg: ", ffmpeg_stderr)


try:
 print(ffmpeg_stdout[:100].decode('utf-8'))
except UnicodeDecodeError:
 print(ffmpeg_stdout[:100].decode('latin-1', errors='ignore'))

return ffmpeg_stdout


This outputs an audio file. If I look at the console I see some messages. I have removed the lengthier stuff and shown only what I find the most interesting :


[mpegts @ 0000021b8576a380] probing stream 0 pp:1457
[mpegts @ 0000021b8576a380] probed stream 0
[mpegts @ 0000021b8576a380] parser not found for codec bin_data, packets or times may be invalid.
For transform of length 120, inverse, mdct_float, flags: [aligned, out_of_place], found 6 matches:
 1: mdct_inv_float_avx2 - type: mdct_float, len: [16, ∞], factors[2]: [2, any], flags: [aligned, out_of_place, inv_only], prio: 544
 2: mdct_pfa_15xM_inv_float_c - type: mdct_float, len: [30, ∞], factors[2]: [15, any], flags: [unaligned, out_of_place, inv_only], prio: 304
 3: mdct_pfa_5xM_inv_float_c - type: mdct_float, len: [10, ∞], factors[2]: [5, any], flags: [unaligned, out_of_place, inv_only], prio: 144
 4: mdct_pfa_3xM_inv_float_c - type: mdct_float, len: [6, ∞], factors[2]: [3, any], flags: [unaligned, out_of_place, inv_only], prio: 112
 5: mdct_inv_float_c - type: mdct_float, len: [2, ∞], factors[2]: [2, any], flags: [unaligned, out_of_place, inv_only], prio: 96
 6: mdct_naive_inv_float_c - type: mdct_float, len: [2, ∞], factors[2]: [2, any], flags: [unaligned, out_of_place, inv_only], prio: -130976
For transform of length 60, inverse, fft_float, flags: [aligned, inplace, preshuf, asm_call], found 1 matches:
 1: fft_pfa_15xM_asm_float_avx2 - type: fft_float, len: [60, ∞], factors[2]: [15, 2], flags: [aligned, inplace, out_of_place, preshuf, asm_call], prio: 688
For transform of length 4, inverse, fft_float, flags: [aligned, inplace, preshuf, asm_call], found 1 matches:
 1: fft4_fwd_asm_float_sse2 - type: fft_float, len: 4, factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call], prio: 352
Transform tree:
 mdct_inv_float_avx2 - type: mdct_float, len: 120, factors[2]: [2, any], flags: [aligned, out_of_place, inv_only]
 fft_pfa_15xM_asm_float_avx2 - type: fft_float, len: 60, factors[2]: [15, 2], flags: [aligned, inplace, out_of_place, preshuf, asm_call]
 fft4_fwd_asm_float_sse2 - type: fft_float, len: 4, factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call]
For transform of length 128, inverse, mdct_float, flags: [aligned, out_of_place], found 3 matches:
 1: mdct_inv_float_avx2 - type: mdct_float, len: [16, ∞], factors[2]: [2, any], flags: [aligned, out_of_place, inv_only], prio: 544
 2: mdct_inv_float_c - type: mdct_float, len: [2, ∞], factors[2]: [2, any], flags: [unaligned, out_of_place, inv_only], prio: 96
 3: mdct_naive_inv_float_c - type: mdct_float, len: [2, ∞], factors[2]: [2, any], flags: [unaligned, out_of_place, inv_only], prio: -130976
For transform of length 64, inverse, fft_float, flags: [aligned, inplace, preshuf, asm_call], found 3 matches:
 1: fft_sr_asm_float_avx2 - type: fft_float, len: [64, 131072], factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call], prio: 480
 2: fft_sr_asm_float_fma3 - type: fft_float, len: [64, 131072], factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call], prio: 448
 3: fft_sr_asm_float_avx - type: fft_float, len: [64, 131072], factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call], prio: 416
Transform tree:
 mdct_inv_float_avx2 - type: mdct_float, len: 128, factors[2]: [2, any], flags: [aligned, out_of_place, inv_only]
 fft_sr_asm_float_avx2 - type: fft_float, len: 64, factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call]
For transform of length 480, inverse, mdct_float, flags: [aligned, out_of_place], found 6 matches:
 1: mdct_inv_float_avx2 - type: mdct_float, len: [16, ∞], factors[2]: [2, any], flags: [aligned, out_of_place, inv_only], prio: 544
 2: mdct_pfa_15xM_inv_float_c - type: mdct_float, len: [30, ∞], factors[2]: [15, any], flags: [unaligned, out_of_place, inv_only], prio: 304
 3: mdct_pfa_5xM_inv_float_c - type: mdct_float, len: [10, ∞], factors[2]: [5, any], flags: [unaligned, out_of_place, inv_only], prio: 144
 4: mdct_pfa_3xM_inv_float_c - type: mdct_float, len: [6, ∞], factors[2]: [3, any], flags: [unaligned, out_of_place, inv_only], prio: 112
 5: mdct_inv_float_c - type: mdct_float, len: [2, ∞], factors[2]: [2, any], flags: [unaligned, out_of_place, inv_only], prio: 96
 6: mdct_naive_inv_float_c - type: mdct_float, len: [2, ∞], factors[2]: [2, any], flags: [unaligned, out_of_place, inv_only], prio: -130976
For transform of length 240, inverse, fft_float, flags: [aligned, inplace, preshuf, asm_call], found 1 matches:
 1: fft_pfa_15xM_asm_float_avx2 - type: fft_float, len: [60, ∞], factors[2]: [15, 2], flags: [aligned, inplace, out_of_place, preshuf, asm_call], prio: 688
For transform of length 16, inverse, fft_float, flags: [aligned, inplace, preshuf, asm_call], found 2 matches:
 1: fft16_asm_float_fma3 - type: fft_float, len: 16, factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call], prio: 512
 2: fft16_asm_float_avx - type: fft_float, len: 16, factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call], prio: 480
Transform tree:
 mdct_inv_float_avx2 - type: mdct_float, len: 480, factors[2]: [2, any], flags: [aligned, out_of_place, inv_only]
 fft_pfa_15xM_asm_float_avx2 - type: fft_float, len: 240, factors[2]: [15, 2], flags: [aligned, inplace, out_of_place, preshuf, asm_call]
 fft16_asm_float_fma3 - type: fft_float, len: 16, factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call]
For transform of length 512, inverse, mdct_float, flags: [aligned, out_of_place], found 3 matches:
 1: mdct_inv_float_avx2 - type: mdct_float, len: [16, ∞], factors[2]: [2, any], flags: [aligned, out_of_place, inv_only], prio: 544
 2: mdct_inv_float_c - type: mdct_float, len: [2, ∞], factors[2]: [2, any], flags: [unaligned, out_of_place, inv_only], prio: 96
 3: mdct_naive_inv_float_c - type: mdct_float, len: [2, ∞], factors[2]: [2, any], flags: [unaligned, out_of_place, inv_only], prio: -130976
For transform of length 256, inverse, fft_float, flags: [aligned, inplace, preshuf, asm_call], found 3 matches:
 1: fft_sr_asm_float_avx2 - type: fft_float, len: [64, 131072], factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call], prio: 480
 2: fft_sr_asm_float_fma3 - type: fft_float, len: [64, 131072], factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call], prio: 448
 3: fft_sr_asm_float_avx - type: fft_float, len: [64, 131072], factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call], prio: 416
Transform tree:
 mdct_inv_float_avx2 - type: mdct_float, len: 512, factors[2]: [2, any], flags: [aligned, out_of_place, inv_only]
 fft_sr_asm_float_avx2 - type: fft_float, len: 256, factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call]
For transform of length 960, inverse, mdct_float, flags: [aligned, out_of_place], found 6 matches:
 1: mdct_inv_float_avx2 - type: mdct_float, len: [16, ∞], factors[2]: [2, any], flags: [aligned, out_of_place, inv_only], prio: 544
 2: mdct_pfa_15xM_inv_float_c - type: mdct_float, len: [30, ∞], factors[2]: [15, any], flags: [unaligned, out_of_place, inv_only], prio: 304
 3: mdct_pfa_5xM_inv_float_c - type: mdct_float, len: [10, ∞], factors[2]: [5, any], flags: [unaligned, out_of_place, inv_only], prio: 144
 4: mdct_pfa_3xM_inv_float_c - type: mdct_float, len: [6, ∞], factors[2]: [3, any], flags: [unaligned, out_of_place, inv_only], prio: 112
 5: mdct_inv_float_c - type: mdct_float, len: [2, ∞], factors[2]: [2, any], flags: [unaligned, out_of_place, inv_only], prio: 96
 6: mdct_naive_inv_float_c - type: mdct_float, len: [2, ∞], factors[2]: [2, any], flags: [unaligned, out_of_place, inv_only], prio: -130976
For transform of length 480, inverse, fft_float, flags: [aligned, inplace, preshuf, asm_call], found 1 matches:
 1: fft_pfa_15xM_asm_float_avx2 - type: fft_float, len: [60, ∞], factors[2]: [15, 2], flags: [aligned, inplace, out_of_place, preshuf, asm_call], prio: 688
For transform of length 32, inverse, fft_float, flags: [aligned, inplace, preshuf, asm_call], found 2 matches:
 1: fft32_asm_float_fma3 - type: fft_float, len: 32, factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call], prio: 512
 2: fft32_asm_float_avx - type: fft_float, len: 32, factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call], prio: 480
Transform tree:
 mdct_inv_float_avx2 - type: mdct_float, len: 960, factors[2]: [2, any], flags: [aligned, out_of_place, inv_only]
 fft_pfa_15xM_asm_float_avx2 - type: fft_float, len: 480, factors[2]: [15, 2], flags: [aligned, inplace, out_of_place, preshuf, asm_call]
 fft32_asm_float_fma3 - type: fft_float, len: 32, factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call]
For transform of length 1024, inverse, mdct_float, flags: [aligned, out_of_place], found 3 matches:
 1: mdct_inv_float_avx2 - type: mdct_float, len: [16, ∞], factors[2]: [2, any], flags: [aligned, out_of_place, inv_only], prio: 544
 2: mdct_inv_float_c - type: mdct_float, len: [2, ∞], factors[2]: [2, any], flags: [unaligned, out_of_place, inv_only], prio: 96
 3: mdct_naive_inv_float_c - type: mdct_float, len: [2, ∞], factors[2]: [2, any], flags: [unaligned, out_of_place, inv_only], prio: -130976
For transform of length 512, inverse, fft_float, flags: [aligned, inplace, preshuf, asm_call], found 3 matches:
 1: fft_sr_asm_float_avx2 - type: fft_float, len: [64, 131072], factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call], prio: 480
 2: fft_sr_asm_float_fma3 - type: fft_float, len: [64, 131072], factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call], prio: 448
 3: fft_sr_asm_float_avx - type: fft_float, len: [64, 131072], factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call], prio: 416
Transform tree:
 mdct_inv_float_avx2 - type: mdct_float, len: 1024, factors[2]: [2, any], flags: [aligned, out_of_place, inv_only]
 fft_sr_asm_float_avx2 - type: fft_float, len: 512, factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call]
For transform of length 1024, forward, mdct_float, flags: [aligned, out_of_place], found 2 matches:
 1: mdct_fwd_float_c - type: mdct_float, len: [2, ∞], factors[2]: [2, any], flags: [unaligned, out_of_place, fwd_only], prio: 96
 2: mdct_naive_fwd_float_c - type: mdct_float, len: [2, ∞], factors[2]: [2, any], flags: [unaligned, out_of_place, fwd_only], prio: -130976
For transform of length 512, forward, fft_float, flags: [aligned, inplace, preshuf], found 5 matches:
 1: fft_sr_ns_float_avx2 - type: fft_float, len: [64, 131072], factor: 2, flags: [aligned, inplace, out_of_place, preshuf], prio: 480
 2: fft_sr_ns_float_fma3 - type: fft_float, len: [64, 131072], factor: 2, flags: [aligned, inplace, out_of_place, preshuf], prio: 448
 3: fft_sr_ns_float_avx - type: fft_float, len: [64, 131072], factor: 2, flags: [aligned, inplace, out_of_place, preshuf], prio: 416
 4: fft_pfa_ns_float_c - type: fft_float, len: [6, ∞], factors[2]: [7, 5, 3, 2, any], flags: [unaligned, inplace, out_of_place, preshuf], prio: 112
 5: fft512_ns_float_c - type: fft_float, len: 512, factor: 2, flags: [unaligned, inplace, out_of_place, preshuf], prio: 96
Transform tree:
 mdct_fwd_float_c - type: mdct_float, len: 1024, factors[2]: [2, any], flags: [unaligned, out_of_place, fwd_only]
 fft_sr_ns_float_avx2 - type: fft_float, len: 512, factor: 2, flags: [aligned, inplace, out_of_place, preshuf]
For transform of length 64, inverse, mdct_float, flags: [aligned, out_of_place], found 3 matches:
 1: mdct_inv_float_avx2 - type: mdct_float, len: [16, ∞], factors[2]: [2, any], flags: [aligned, out_of_place, inv_only], prio: 544
 2: mdct_inv_float_c - type: mdct_float, len: [2, ∞], factors[2]: [2, any], flags: [unaligned, out_of_place, inv_only], prio: 96
 3: mdct_naive_inv_float_c - type: mdct_float, len: [2, ∞], factors[2]: [2, any], flags: [unaligned, out_of_place, inv_only], prio: -130976
For transform of length 32, inverse, fft_float, flags: [aligned, inplace, preshuf, asm_call], found 2 matches:
 1: fft32_asm_float_fma3 - type: fft_float, len: 32, factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call], prio: 512
 2: fft32_asm_float_avx - type: fft_float, len: 32, factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call], prio: 480
Transform tree:
 mdct_inv_float_avx2 - type: mdct_float, len: 64, factors[2]: [2, any], flags: [aligned, out_of_place, inv_only]
 fft32_asm_float_fma3 - type: fft_float, len: 32, factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call]
For transform of length 64, inverse, mdct_float, flags: [aligned, out_of_place], found 3 matches:
 1: mdct_inv_float_avx2 - type: mdct_float, len: [16, ∞], factors[2]: [2, any], flags: [aligned, out_of_place, inv_only], prio: 544
 2: mdct_inv_float_c - type: mdct_float, len: [2, ∞], factors[2]: [2, any], flags: [unaligned, out_of_place, inv_only], prio: 96
 3: mdct_naive_inv_float_c - type: mdct_float, len: [2, ∞], factors[2]: [2, any], flags: [unaligned, out_of_place, inv_only], prio: -130976
For transform of length 32, inverse, fft_float, flags: [aligned, inplace, preshuf, asm_call], found 2 matches:
 1: fft32_asm_float_fma3 - type: fft_float, len: 32, factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call], prio: 512
 2: fft32_asm_float_avx - type: fft_float, len: 32, factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call], prio: 480
Transform tree:
 mdct_inv_float_avx2 - type: mdct_float, len: 64, factors[2]: [2, any], flags: [aligned, out_of_place, inv_only]
 fft32_asm_float_fma3 - type: fft_float, len: 32, factor: 2, flags: [aligned, inplace, out_of_place, preshuf, asm_call]
[mpegts @ 0000021b8576a380] max_analyze_duration 5000000 reached at 5005000 microseconds st:0
[mpegts @ 0000021b8576a380] After avformat_find_stream_info() pos: 5403308 bytes read:5404624 seeks:0 frames:365
Input #0, mpegts, from 'fd:':
 Duration: N/A, start: 1.400000, bitrate: 130 kb/s
 Program 1
 Metadata:
 service_name : Service01
 service_provider: FFmpeg
 Stream #0:0[0x100], 152, 1/90000: Data: bin_data ([6][0][0][0] / 0x0006), 0/1
 Stream #0:1[0x101](und), 213, 1/90000: Audio: aac (LC) ([15][0][0][0] / 0x000F), 44100 Hz, stereo, fltp, 130 kb/s
Successfully opened the file.
Parsing a group of options: output url output.mp4.
Applying option c (codec name) with argument copy.
Successfully parsed a group of options.
Opening an output file: output.mp4.
[out#0/mp4 @ 0000021b89b251c0] No explicit maps, mapping streams automatically...
[aost#0:0/copy @ 0000021b89b8d800] Created audio stream from input stream 0:1
[file @ 0000021b89586680] Setting default whitelist 'file,crypto,data'
Successfully opened the file.
Stream mapping:
 Stream #0:1 -> #0:0 (copy)
Output #0, mp4, to 'output.mp4':
 Metadata:
 encoder : Lavf60.20.100
 Stream #0:0(und), 0, 1/44100: Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 130 kb/s
[out#0/mp4 @ 0000021b89b251c0] Starting thread...
[in#0/mpegts @ 0000021b85724080] Starting thread...
Automatically inserted bitstream filter 'aac_adtstoasc'; args=''
[in#0/mpegts @ 0000021b85724080] EOF while reading inputpeed= 40x
[in#0/mpegts @ 0000021b85724080] Terminating thread with return code 0 (success)
[out#0/mp4 @ 0000021b89b251c0] All streams finished
[out#0/mp4 @ 0000021b89b251c0] Terminating thread with return code 0 (success)
[AVIOContext @ 0000021b87146340] Statistics: 2723207 bytes written, 2 seeks, 14 writeouts
[out#0/mp4 @ 0000021b89b251c0] Output file #0 (output.mp4):
[out#0/mp4 @ 0000021b89b251c0] Output stream #0:0 (audio): 7232 packets muxed (2737451 bytes);
[out#0/mp4 @ 0000021b89b251c0] Total: 7232 packets (2737451 bytes) muxed
[out#0/mp4 @ 0000021b89b251c0] video:0kB audio:2673kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
size= 2659kB time=00:02:47.92 bitrate= 129.7kbits/s speed=41.3x
 Metadata:
 encoder : Lavf60.20.100
 Stream #0:0(und), 0, 1/44100: Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 130 kb/s
[out#0/mp4 @ 0000021b89b251c0] Starting thread...
[in#0/mpegts @ 0000021b85724080] Starting thread...
Automatically inserted bitstream filter 'aac_adtstoasc'; args=''
[in#0/mpegts @ 0000021b85724080] EOF while reading inputpeed= 40x
[in#0/mpegts @ 0000021b85724080] Terminating thread with return code 0 (success)
[out#0/mp4 @ 0000021b89b251c0] All streams finished
[out#0/mp4 @ 0000021b89b251c0] Terminating thread with return code 0 (success)
[AVIOContext @ 0000021b87146340] Statistics: 2723207 bytes written, 2 seeks, 14 writeouts
[out#0/mp4 @ 0000021b89b251c0] Output file #0 (output.mp4):
[out#0/mp4 @ 0000021b89b251c0] Output stream #0:0 (audio): 7232 packets muxed (2737451 bytes);
[out#0/mp4 @ 0000021b89b251c0] Total: 7232 packets (2737451 bytes) muxed
[out#0/mp4 @ 0000021b89b251c0] video:0kB audio:2673kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
size= 2659kB time=00:02:47.92 bitrate= 129.7kbits/s speed=41.3x
[in#0/mpegts @ 0000021b85724080] Starting thread...
Automatically inserted bitstream filter 'aac_adtstoasc'; args=''
[in#0/mpegts @ 0000021b85724080] EOF while reading inputpeed= 40x
[in#0/mpegts @ 0000021b85724080] Terminating thread with return code 0 (success)
[out#0/mp4 @ 0000021b89b251c0] All streams finished
[out#0/mp4 @ 0000021b89b251c0] Terminating thread with return code 0 (success)
[AVIOContext @ 0000021b87146340] Statistics: 2723207 bytes written, 2 seeks, 14 writeouts
[out#0/mp4 @ 0000021b89b251c0] Output file #0 (output.mp4):
[out#0/mp4 @ 0000021b89b251c0] Output stream #0:0 (audio): 7232 packets muxed (2737451 bytes);
[out#0/mp4 @ 0000021b89b251c0] Total: 7232 packets (2737451 bytes) muxed
[out#0/mp4 @ 0000021b89b251c0] video:0kB audio:2673kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
size= 2659kB time=00:02:47.92 bitrate= 129.7kbits/s speed=41.3x
[out#0/mp4 @ 0000021b89b251c0] All streams finished
[out#0/mp4 @ 0000021b89b251c0] Terminating thread with return code 0 (success)
[AVIOContext @ 0000021b87146340] Statistics: 2723207 bytes written, 2 seeks, 14 writeouts
[out#0/mp4 @ 0000021b89b251c0] Output file #0 (output.mp4):
[out#0/mp4 @ 0000021b89b251c0] Output stream #0:0 (audio): 7232 packets muxed (2737451 bytes);
[out#0/mp4 @ 0000021b89b251c0] Total: 7232 packets (2737451 bytes) muxed
[out#0/mp4 @ 0000021b89b251c0] video:0kB audio:2673kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
size= 2659kB time=00:02:47.92 bitrate= 129.7kbits/s speed=41.3x
[out#0/mp4 @ 0000021b89b251c0] Output file #0 (output.mp4):
[out#0/mp4 @ 0000021b89b251c0] Output stream #0:0 (audio): 7232 packets muxed (2737451 bytes);
[out#0/mp4 @ 0000021b89b251c0] Total: 7232 packets (2737451 bytes) muxed
[out#0/mp4 @ 0000021b89b251c0] video:0kB audio:2673kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
size= 2659kB time=00:02:47.92 bitrate= 129.7kbits/s speed=41.3x
[out#0/mp4 @ 0000021b89b251c0] Total: 7232 packets (2737451 bytes) muxed
[out#0/mp4 @ 0000021b89b251c0] video:0kB audio:2673kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
size= 2659kB time=00:02:47.92 bitrate= 129.7kbits/s speed=41.3x
[out#0/mp4 @ 0000021b89b251c0] video:0kB audio:2673kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
size= 2659kB time=00:02:47.92 bitrate= 129.7kbits/s speed=41.3x
[in#0/mpegts @ 0000021b85724080] Input file #0 (fd:):
size= 2659kB time=00:02:47.92 bitrate= 129.7kbits/s speed=41.3x
[in#0/mpegts @ 0000021b85724080] Input file #0 (fd:):
[in#0/mpegts @ 0000021b85724080] Input file #0 (fd:):
[in#0/mpegts @ 0000021b85724080] Input stream #0:1 (audio): 7232 packets read (2737451 bytes);
[in#0/mpegts @ 0000021b85724080] Total: 7232 packets (2737451 bytes) demuxed
[AVIOContext @ 0000021b85744880] Statistics: 27226912 bytes read, 0 seeks


It seems to me that the video data is being interpreted as bin_data and no codec is found for it. What is going on here ?


Must YT_DLP data be converted to some other format before being read by FFMPEG ?


Thank you.


-
Using FFmpeg encode and UDP with a Webcam ?
14 mars, par RendresI'm trying to get frames from a Webcam using OpenCV, encode them with FFmpeg and send them using UDP.


I did before a similar project that instead of sending the packets with UDP, it saved them in a video file.


My code is.


#include 
#include 
#include 
#include 

extern "C" {
#include <libavcodec></libavcodec>avcodec.h>
#include <libavformat></libavformat>avformat.h>
#include <libavutil></libavutil>opt.h>
#include <libavutil></libavutil>imgutils.h>
#include <libavutil></libavutil>mathematics.h>
#include <libswscale></libswscale>swscale.h>
#include <libswresample></libswresample>swresample.h>
}

#include <opencv2></opencv2>opencv.hpp>

using namespace std;
using namespace cv;

#define WIDTH 640
#define HEIGHT 480
#define CODEC_ID AV_CODEC_ID_H264
#define STREAM_PIX_FMT AV_PIX_FMT_YUV420P

static AVFrame *frame, *pFrameBGR;

int main(int argc, char **argv)
{
VideoCapture cap(0);
const char *url = "udp://127.0.0.1:8080";

AVFormatContext *formatContext;
AVStream *stream;
AVCodec *codec;
AVCodecContext *c;
AVDictionary *opts = NULL;

int ret, got_packet;

if (!cap.isOpened())
{
 return -1;
}

av_log_set_level(AV_LOG_TRACE);

av_register_all();
avformat_network_init();

avformat_alloc_output_context2(&formatContext, NULL, "h264", url);
if (!formatContext)
{
 av_log(NULL, AV_LOG_FATAL, "Could not allocate an output context for '%s'.\n", url);
}

codec = avcodec_find_encoder(CODEC_ID);
if (!codec)
{
 av_log(NULL, AV_LOG_ERROR, "Could not find encoder.\n");
}

stream = avformat_new_stream(formatContext, codec);

c = avcodec_alloc_context3(codec);

stream->id = formatContext->nb_streams - 1;
stream->time_base = (AVRational){1, 25};

c->codec_id = CODEC_ID;
c->bit_rate = 400000;
c->width = WIDTH;
c->height = HEIGHT;
c->time_base = stream->time_base;
c->gop_size = 12;
c->pix_fmt = STREAM_PIX_FMT;

if (formatContext->flags & AVFMT_GLOBALHEADER)
 c->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;

av_dict_set(&opts, "preset", "fast", 0);

av_dict_set(&opts, "tune", "zerolatency", 0);

ret = avcodec_open2(c, codec, NULL);
if (ret < 0)
{
 av_log(NULL, AV_LOG_ERROR, "Could not open video codec.\n");
}

pFrameBGR = av_frame_alloc();
if (!pFrameBGR)
{
 av_log(NULL, AV_LOG_ERROR, "Could not allocate video frame.\n");
}

frame = av_frame_alloc();
if (!frame)
{
 av_log(NULL, AV_LOG_ERROR, "Could not allocate video frame.\n");
}

frame->format = c->pix_fmt;
frame->width = c->width;
frame->height = c->height;

ret = avcodec_parameters_from_context(stream->codecpar, c);
if (ret < 0)
{
 av_log(NULL, AV_LOG_ERROR, "Could not open video codec.\n");
}

av_dump_format(formatContext, 0, url, 1);

ret = avformat_write_header(formatContext, NULL);
if (ret != 0)
{
 av_log(NULL, AV_LOG_ERROR, "Failed to connect to '%s'.\n", url);
}

Mat image(Size(HEIGHT, WIDTH), CV_8UC3);
SwsContext *swsctx = sws_getContext(WIDTH, HEIGHT, AV_PIX_FMT_BGR24, WIDTH, HEIGHT, AV_PIX_FMT_YUV420P, SWS_BILINEAR, NULL, NULL, NULL);
int frame_pts = 0;

while (1)
{
 cap >> image;

 int numBytesYUV = av_image_get_buffer_size(STREAM_PIX_FMT, WIDTH, HEIGHT, 1);
 uint8_t *bufferYUV = (uint8_t *)av_malloc(numBytesYUV * sizeof(uint8_t));

 avpicture_fill((AVPicture *)pFrameBGR, image.data, AV_PIX_FMT_BGR24, WIDTH, HEIGHT);
 avpicture_fill((AVPicture *)frame, bufferYUV, STREAM_PIX_FMT, WIDTH, HEIGHT);

 sws_scale(swsctx, (uint8_t const *const *)pFrameBGR->data, pFrameBGR->linesize, 0, HEIGHT, frame->data, frame->linesize);

 AVPacket pkt = {0};
 av_init_packet(&pkt);

 frame->pts = frame_pts;

 ret = avcodec_encode_video2(c, &pkt, frame, &got_packet);
 if (ret < 0)
 {
 av_log(NULL, AV_LOG_ERROR, "Error encoding frame\n");
 }

 if (got_packet)
 {
 pkt.pts = av_rescale_q_rnd(pkt.pts, c->time_base, stream->time_base, AVRounding(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));
 pkt.dts = av_rescale_q_rnd(pkt.dts, c->time_base, stream->time_base, AVRounding(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));
 pkt.duration = av_rescale_q(pkt.duration, c->time_base, stream->time_base);
 pkt.stream_index = stream->index;

 return av_interleaved_write_frame(formatContext, &pkt);

 cout << "Seguro que si" << endl;
 }
 frame_pts++;
}

avcodec_free_context(&c);
av_frame_free(&frame);
avformat_free_context(formatContext);

return 0;
}


The code compiles but it returns Segmentation fault in the function av_interleaved_write_frame(). I've tried several implementations or several codecs (in this case I'm using libopenh264, but using mpeg2video returns the same segmentation fault). I tried also with av_write_frame() but it returns the same error.


As I told before, I only want to grab frames from a webcam connected via USB, encode them to H264 and send the packets through UDP to another PC.


My console log when I run the executable is.


[100%] Built target display
[OpenH264] this = 0x0x244b4f0, Info:CWelsH264SVCEncoder::SetOption():ENCODER_OPTION_TRACE_CALLBACK callback = 0x7f0c302a87c0.
[libopenh264 @ 0x244aa00] [OpenH264] this = 0x0x244b4f0, Info:CWelsH264SVCEncoder::InitEncoder(), openh264 codec version = 5a5c4f1
[libopenh264 @ 0x244aa00] [OpenH264] this = 0x0x244b4f0, Info:iUsageType = 0,iPicWidth= 640;iPicHeight= 480;iTargetBitrate= 400000;iMaxBitrate= 400000;iRCMode= 0;iPaddingFlag= 0;iTemporalLayerNum= 1;iSpatialLayerNum= 1;fFrameRate= 25.000000f;uiIntraPeriod= 12;eSpsPpsIdStrategy = 0;bPrefixNalAddingCtrl = 0;bSimulcastAVC=0;bEnableDenoise= 0;bEnableBackgroundDetection= 1;bEnableSceneChangeDetect = 1;bEnableAdaptiveQuant= 1;bEnableFrameSkip= 0;bEnableLongTermReference= 0;iLtrMarkPeriod= 30, bIsLosslessLink=0;iComplexityMode = 0;iNumRefFrame = 1;iEntropyCodingModeFlag = 0;uiMaxNalSize = 0;iLTRRefNum = 0;iMultipleThreadIdc = 1;iLoopFilterDisableIdc = 0 (offset(alpha/beta): 0,0;iComplexityMode = 0,iMaxQp = 51;iMinQp = 0)
[libopenh264 @ 0x244aa00] [OpenH264] this = 0x0x244b4f0, Info:sSpatialLayers[0]: .iVideoWidth= 640; .iVideoHeight= 480; .fFrameRate= 25.000000f; .iSpatialBitrate= 400000; .iMaxSpatialBitrate= 400000; .sSliceArgument.uiSliceMode= 1; .sSliceArgument.iSliceNum= 0; .sSliceArgument.uiSliceSizeConstraint= 1500;uiProfileIdc = 66;uiLevelIdc = 41
[libopenh264 @ 0x244aa00] [OpenH264] this = 0x0x244b4f0, Warning:SliceArgumentValidationFixedSliceMode(), unsupported setting with Resolution and uiSliceNum combination under RC on! So uiSliceNum is changed to 6!
[libopenh264 @ 0x244aa00] [OpenH264] this = 0x0x244b4f0, Info:Setting MaxSpatialBitrate (400000) the same at SpatialBitrate (400000) will make the actual bit rate lower than SpatialBitrate
[libopenh264 @ 0x244aa00] [OpenH264] this = 0x0x244b4f0, Warning:bEnableFrameSkip = 0,bitrate can't be controlled for RC_QUALITY_MODE,RC_BITRATE_MODE and RC_TIMESTAMP_MODE without enabling skip frame.
[libopenh264 @ 0x244aa00] [OpenH264] this = 0x0x244b4f0, Warning:Change QP Range from(0,51) to (12,42)
[libopenh264 @ 0x244aa00] [OpenH264] this = 0x0x244b4f0, Info:WELS CPU features/capacities (0x4007fe3f) detected: HTT: Y, MMX: Y, MMXEX: Y, SSE: Y, SSE2: Y, SSE3: Y, SSSE3: Y, SSE4.1: Y, SSE4.2: Y, AVX: Y, FMA: Y, X87-FPU: Y, 3DNOW: N, 3DNOWEX: N, ALTIVEC: N, CMOV: Y, MOVBE: Y, AES: Y, NUMBER OF LOGIC PROCESSORS ON CHIP: 8, CPU CACHE LINE SIZE (BYTES): 64
[libopenh264 @ 0x244aa00] [OpenH264] this = 0x0x244b4f0, Info:WelsInitEncoderExt() exit, overall memory usage: 4542878 bytes
[libopenh264 @ 0x244aa00] [OpenH264] this = 0x0x244b4f0, Info:WelsInitEncoderExt(), pCtx= 0x0x245a400.
Output #0, h264, to 'udp://192.168.100.39:8080':
Stream #0:0, 0, 1/25: Video: h264 (libopenh264), 1 reference frame, yuv420p, 640x480 (0x0), 0/1, q=2-31, 400 kb/s, 25 tbn
[libopenh264 @ 0x244aa00] [OpenH264] this = 0x0x244b4f0, Debug:RcUpdateIntraComplexity iFrameDqBits = 385808,iQStep= 2016,iIntraCmplx = 777788928
[libopenh264 @ 0x244aa00] [OpenH264] this = 0x0x244b4f0, Debug:[Rc]Layer 0: Frame timestamp = 0, Frame type = 2, encoding_qp = 30, average qp = 30, max qp = 33, min qp = 27, index = 0, iTid = 0, used = 385808, bitsperframe = 16000, target = 64000, remainingbits = -257808, skipbuffersize = 200000
[libopenh264 @ 0x244aa00] [OpenH264] this = 0x0x244b4f0, Debug:WelsEncoderEncodeExt() OutputInfo iLayerNum = 2,iFrameSize = 48252
[libopenh264 @ 0x244aa00] [OpenH264] this = 0x0x244b4f0, Debug:WelsEncoderEncodeExt() OutputInfo iLayerId = 0,iNalType = 0,iNalCount = 2, first Nal Length=18,uiSpatialId = 0,uiTemporalId = 0,iSubSeqId = 0
[libopenh264 @ 0x244aa00] [OpenH264] this = 0x0x244b4f0, Debug:WelsEncoderEncodeExt() OutputInfo iLayerId = 1,iNalType = 1,iNalCount = 6, first Nal Length=6057,uiSpatialId = 0,uiTemporalId = 0,iSubSeqId = 0
[libopenh264 @ 0x244aa00] 6 slices
./scriptBuild.sh: line 20: 10625 Segmentation fault (core dumped) ./display


As you can see, FFmpeg uses libopenh264 and configures it correctly. However, no matter what. It always returns the same Segmentation fault error...


I've used commands like this.


ffmpeg -s 640x480 -f video4linux2 -i /dev/video0 -r 30 -vcodec libopenh264 -an -f h264 udp://127.0.0.1:8080


And it works perfectly, but I need to process the frames before sending them. Thats why I'm trying to use the libs.


My FFmpeg version is.


ffmpeg version 3.3.6 Copyright (c) 2000-2017 the FFmpeg developers
built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04.3)
configuration: --disable-yasm --enable-shared --enable-libopenh264 --cc='gcc -fPIC'
libavutil 55. 58.100 / 55. 58.100
libavcodec 57. 89.100 / 57. 89.100
libavformat 57. 71.100 / 57. 71.100
libavdevice 57. 6.100 / 57. 6.100
libavfilter 6. 82.100 / 6. 82.100
libswscale 4. 6.100 / 4. 6.100
libswresample 2. 7.100 / 2. 7.100


I tried to get more information of the error using gbd, but it didn't give me debugging info.


How can I solve this problem ?


-
Encoding/Decoding H264 using libav in C++ [closed]
20 mai, par gbock93I want to build an application to


- 

- capture frames in YUYV 4:2:2 format
- encode them to H264
- send over network
- decode the received data
- display the video stream












To do so I wrote 2 classes, H264Encoder and H264Decoder.


I post only the .cpp contents, the .h are trivial :


H264Encoder.cpp


#include 

#include <stdexcept>
#include <iostream>

H264Encoder::H264Encoder(unsigned int width_, unsigned int height_, unsigned int fps_):
 m_width(width_),
 m_height(height_),
 m_fps(fps_),
 m_frame_index(0),
 m_context(nullptr),
 m_frame(nullptr),
 m_packet(nullptr),
 m_sws_ctx(nullptr)
{
 // Find the video codec
 AVCodec* codec;
 codec = avcodec_find_encoder(AV_CODEC_ID_H264);
 if (!codec)
 throw std::runtime_error("[Encoder]: Error: Codec not found");

 // Allocate codec
 m_context = avcodec_alloc_context3(codec);
 if (!m_context)
 throw std::runtime_error("[Encoder]: Error: Could not allocate codec context");

 // Configure codec
 av_opt_set(m_context->priv_data, "preset", "ultrafast", 0);
 av_opt_set(m_context->priv_data, "tune", "zerolatency", 0);
 av_opt_set(m_context->priv_data, "crf", "35", 0); // Range: [0; 51], sane range: [18; 26], lower -> higher compression

 m_context->width = (int)width_;
 m_context->height = (int)height_;
 m_context->time_base = {1, (int)fps_};
 m_context->framerate = {(int)fps_, 1};
 m_context->codec_id = AV_CODEC_ID_H264;
 m_context->pix_fmt = AV_PIX_FMT_YUV420P; // H265|4 codec take as input only AV_PIX_FMT_YUV420P
 m_context->bit_rate = 400000;
 m_context->gop_size = 10;
 m_context->max_b_frames = 1;

 // Open codec
 if (avcodec_open2(m_context, codec, nullptr) < 0)
 throw std::runtime_error("[Encoder]: Error: Could not open codec");

 // Allocate frame and its buffer
 m_frame = av_frame_alloc();
 if (!m_frame) 
 throw std::runtime_error("[Encoder]: Error: Could not allocate frame");

 m_frame->format = m_context->pix_fmt;
 m_frame->width = m_context->width;
 m_frame->height = m_context->height;

 if (av_frame_get_buffer(m_frame, 0) < 0)
 throw std::runtime_error("[Encoder]: Error: Cannot allocate frame buffer");
 
 // Allocate packet
 m_packet = av_packet_alloc();
 if (!m_packet) 
 throw std::runtime_error("[Encoder]: Error: Could not allocate packet");

 // Convert from YUYV422 to YUV420P
 m_sws_ctx = sws_getContext(
 width_, height_, AV_PIX_FMT_YUYV422,
 width_, height_, AV_PIX_FMT_YUV420P,
 SWS_BILINEAR, nullptr, nullptr, nullptr
 );
 if (!m_sws_ctx) 
 throw std::runtime_error("[Encoder]: Error: Could not allocate sws context");

 //
 printf("[Encoder]: H264Encoder ready.\n");
}

H264Encoder::~H264Encoder()
{
 sws_freeContext(m_sws_ctx);
 av_packet_free(&m_packet);
 av_frame_free(&m_frame);
 avcodec_free_context(&m_context);

 printf("[Encoder]: H264Encoder destroyed.\n");
}

std::vector H264Encoder::encode(const cv::Mat& img_)
{
 /*
 - YUYV422 is a packed format. It has 3 components (av_pix_fmt_desc_get((AVPixelFormat)AV_PIX_FMT_YUYV422)->nb_components == 3) but
 data is stored in a single plane (av_pix_fmt_count_planes((AVPixelFormat)AV_PIX_FMT_YUYV422) == 1).
 - YUV420P is a planar format. It has 3 components (av_pix_fmt_desc_get((AVPixelFormat)AV_PIX_FMT_YUV420P)->nb_components == 3) and
 each component is stored in a separate plane (av_pix_fmt_count_planes((AVPixelFormat)AV_PIX_FMT_YUV420P) == 3) with its
 own stride.
 */
 std::cout << "[Encoder]" << std::endl;
 std::cout << "[Encoder]: Encoding img " << img_.cols << "x" << img_.rows << " | element size " << img_.elemSize() << std::endl;
 assert(img_.elemSize() == 2);

 uint8_t* input_data[1] = {(uint8_t*)img_.data};
 int input_linesize[1] = {2 * (int)m_width};
 
 if (av_frame_make_writable(m_frame) < 0)
 throw std::runtime_error("[Encoder]: Error: Cannot make frame data writable");

 // Convert from YUV422 image to YUV420 frame. Apply scaling if necessary
 sws_scale(
 m_sws_ctx,
 input_data, input_linesize, 0, m_height,
 m_frame->data, m_frame->linesize
 );
 m_frame->pts = m_frame_index;

 int n_planes = av_pix_fmt_count_planes((AVPixelFormat)m_frame->format);
 std::cout << "[Encoder]: Sending Frame " << m_frame_index << " with dimensions " << m_frame->width << "x" << m_frame->height << "x" << n_planes << std::endl;
 for (int i=0; iframerate.num) + 1;
 break;
 case AVERROR(EAGAIN):
 throw std::runtime_error("[Encoder]: avcodec_send_frame: EAGAIN");
 case AVERROR_EOF:
 throw std::runtime_error("[Encoder]: avcodec_send_frame: EOF");
 case AVERROR(EINVAL):
 throw std::runtime_error("[Encoder]: avcodec_send_frame: EINVAL");
 case AVERROR(ENOMEM):
 throw std::runtime_error("[Encoder]: avcodec_send_frame: ENOMEM");
 default:
 throw std::runtime_error("[Encoder]: avcodec_send_frame: UNKNOWN");
 }

 // Receive packet from codec
 std::vector result;
 while(ret >= 0)
 {
 ret = avcodec_receive_packet(m_context, m_packet);

 switch (ret)
 {
 case 0:
 std::cout << "[Encoder]: Received packet from codec of size " << m_packet->size << " bytes " << std::endl;
 result.insert(result.end(), m_packet->data, m_packet->data + m_packet->size);
 av_packet_unref(m_packet);
 break;

 case AVERROR(EAGAIN):
 std::cout << "[Encoder]: avcodec_receive_packet: EAGAIN" << std::endl;
 break;
 case AVERROR_EOF:
 std::cout << "[Encoder]: avcodec_receive_packet: EOF" << std::endl;
 break;
 case AVERROR(EINVAL):
 throw std::runtime_error("[Encoder]: avcodec_receive_packet: EINVAL");
 default:
 throw std::runtime_error("[Encoder]: avcodec_receive_packet: UNKNOWN");
 }
 }

 std::cout << "[Encoder]: Encoding complete" << std::endl;
 return result;
}
</iostream></stdexcept>

H264Decoder.cpp


#include 

#include <iostream>
#include <stdexcept>

H264Decoder::H264Decoder():
 m_context(nullptr),
 m_frame(nullptr),
 m_packet(nullptr)
{
 // Find the video codec
 AVCodec* codec;
 codec = avcodec_find_decoder(AV_CODEC_ID_H264);
 if (!codec)
 throw std::runtime_error("[Decoder]: Error: Codec not found");

 // Allocate codec
 m_context = avcodec_alloc_context3(codec);
 if (!m_context)
 throw std::runtime_error("[Decoder]: Error: Could not allocate codec context");

 // Open codec
 if (avcodec_open2(m_context, codec, nullptr) < 0)
 throw std::runtime_error("[Decoder]: Error: Could not open codec");

 // Allocate frame
 m_frame = av_frame_alloc();
 if (!m_frame)
 throw std::runtime_error("[Decoder]: Error: Could not allocate frame");

 // Allocate packet
 m_packet = av_packet_alloc();
 if (!m_packet) 
 throw std::runtime_error("[Decoder]: Error: Could not allocate packet");

 //
 printf("[Decoder]: H264Decoder ready.\n");
}

H264Decoder::~H264Decoder()
{
 av_packet_free(&m_packet);
 av_frame_free(&m_frame);
 avcodec_free_context(&m_context);

 printf("[Decoder]: H264Decoder destroyed.\n");
}

bool H264Decoder::decode(uint8_t* data_, size_t size_, cv::Mat& img_)
{
 std::cout << "[Decoder]" << std::endl;
 std::cout << "[Decoder]: decoding " << size_ << " bytes of data" << std::endl;

 // Fill packet
 m_packet->data = data_;
 m_packet->size = size_;

 if (size_ == 0)
 return false;

 // Send packet to codec
 int send_result = avcodec_send_packet(m_context, m_packet);

 switch (send_result)
 {
 case 0:
 std::cout << "[Decoder]: Sent packet to codec" << std::endl;
 break;
 case AVERROR(EAGAIN):
 throw std::runtime_error("[Decoder]: avcodec_send_packet: EAGAIN");
 case AVERROR_EOF:
 throw std::runtime_error("[Decoder]: avcodec_send_packet: EOF");
 case AVERROR(EINVAL):
 throw std::runtime_error("[Decoder]: avcodec_send_packet: EINVAL");
 case AVERROR(ENOMEM):
 throw std::runtime_error("[Decoder]: avcodec_send_packet: ENOMEM");
 default:
 throw std::runtime_error("[Decoder]: avcodec_send_packet: UNKNOWN");
 }

 // Receive frame from codec
 int n_planes;
 uint8_t* output_data[1];
 int output_line_size[1];

 int receive_result = avcodec_receive_frame(m_context, m_frame);

 switch (receive_result)
 {
 case 0:
 n_planes = av_pix_fmt_count_planes((AVPixelFormat)m_frame->format);
 std::cout << "[Decoder]: Received Frame with dimensions " << m_frame->width << "x" << m_frame->height << "x" << n_planes << std::endl;
 for (int i=0; i/
 std::cout << "[Decoder]: Decoding complete" << std::endl;
 return true;
}
</stdexcept></iostream>

To test the two classes I put together a main.cpp to grab a frame, encode/decode and display the decoded frame (no network transmission in place) :


main.cpp


while(...)
{
 // get frame from custom camera class. Format is YUYV 4:2:2
 camera.getFrame(camera_frame);
 // Construct a cv::Mat to represent the grabbed frame
 cv::Mat camera_frame_yuyv = cv::Mat(camera_frame.height, camera_frame.width, CV_8UC2, camera_frame.data.data());
 // Encode image
 std::vector encoded_data = encoder.encode(camera_frame_yuyv);
 if (!encoded_data.empty())
 {
 // Decode image
 cv::Mat decoded_frame;
 if (decoder.decode(encoded_data.data(), encoded_data.size(), decoded_frame))
 {
 // Display image
 cv::imshow("Camera", decoded_frame);
 cv::waitKey(1);
 }
 }
}


Compiling and executing the code I get random results between subsequent executions :


- 

- Sometimes the whole loop runs without problems and I see the decoded image.
- Sometimes the program crashes at the
sws_scale(...)call in the decoder with"Assertion desc failed at src/libswscale/swscale_internal.h:757". - Sometimes the loop runs but I see a black image and the message
Slice parameters 0, 720 are invalidis displayed when executing thesws_scale(...)call in the decoder.








Why is the behaviour so random ? What am I doing wrong with the libav API ?


Some resources I found useful :


- 

- This article on encoding
- This article on decoding






Syndiquer tout le site
