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Bug de détection d’ogg
22 mars 2013, par
Mis à jour : Avril 2013
Langue : français
Type : Video
Autres articles (74)
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Le profil des utilisateurs
12 avril 2011, parChaque utilisateur dispose d’une page de profil lui permettant de modifier ses informations personnelle. Dans le menu de haut de page par défaut, un élément de menu est automatiquement créé à l’initialisation de MediaSPIP, visible uniquement si le visiteur est identifié sur le site.
L’utilisateur a accès à la modification de profil depuis sa page auteur, un lien dans la navigation "Modifier votre profil" est (...) -
Configurer la prise en compte des langues
15 novembre 2010, parAccéder à la configuration et ajouter des langues prises en compte
Afin de configurer la prise en compte de nouvelles langues, il est nécessaire de se rendre dans la partie "Administrer" du site.
De là, dans le menu de navigation, vous pouvez accéder à une partie "Gestion des langues" permettant d’activer la prise en compte de nouvelles langues.
Chaque nouvelle langue ajoutée reste désactivable tant qu’aucun objet n’est créé dans cette langue. Dans ce cas, elle devient grisée dans la configuration et (...) -
Les autorisations surchargées par les plugins
27 avril 2010, parMediaspip core
autoriser_auteur_modifier() afin que les visiteurs soient capables de modifier leurs informations sur la page d’auteurs
Sur d’autres sites (12473)
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Libavcodec : How to tell end of access unit when decoding H.264 stream
22 septembre 2011, par FlameI'm receiving H.264 video over RTP and decoding it with libavcodec. I'm unpackaging the NAL units from the RTP packets before feeding them to avcodec (including reassembling fragmentation units).
I'm trying to show effective decoding frame rate. I used to log the time after a successful decode video call where *got_picture_ptr is non-zero. So far this worked since I only ever got video where there was one slice per frame. But now I receive video where both I and P frames consist of 2 NAL units each, of types 5 and 1 respectively. Now when I feed the either slice of a frame, decode_video return that it got a picture, and the pAVFrame->coded_picture_number is increased from every slice.
How do I go about reliably finding the beginning or end of a video frame/picture/access unit ?
I've dumped out a few NAL units from the stream and run them through h264_analyze from h264bitstream.
Output from h264_analyze on 4 NAL Units
!! Found NAL at offset 695262 (0xA9BDE), size 25 (0x0019) ==================== NAL ==================== forbidden_zero_bit : 0 nal_ref_idc : 1 nal_unit_type : 7 ( Sequence parameter set ) ======= SPS ======= profile_idc : 66 constraint_set0_flag : 1 constraint_set1_flag : 1 constraint_set2_flag : 1 constraint_set3_flag : 0 reserved_zero_4bits : 0 level_idc : 32 seq_parameter_set_id : 0 chroma_format_idc : 0 residual_colour_transform_flag : 0 bit_depth_luma_minus8 : 0 bit_depth_chroma_minus8 : 0 qpprime_y_zero_transform_bypass_flag : 0 seq_scaling_matrix_present_flag : 0 log2_max_frame_num_minus4 : 12 pic_order_cnt_type : 2 log2_max_pic_order_cnt_lsb_minus4 : 0 delta_pic_order_always_zero_flag : 0 offset_for_non_ref_pic : 0 offset_for_top_to_bottom_field : 0 num_ref_frames_in_pic_order_cnt_cycle : 0 num_ref_frames : 1 gaps_in_frame_num_value_allowed_flag : 0 pic_width_in_mbs_minus1 : 79 pic_height_in_map_units_minus1 : 44 frame_mbs_only_flag : 1 mb_adaptive_frame_field_flag : 0 direct_8x8_inference_flag : 1 frame_cropping_flag : 0 frame_crop_left_offset : 0 frame_crop_right_offset : 0 frame_crop_top_offset : 0 frame_crop_bottom_offset : 0 vui_parameters_present_flag : 1 === VUI === aspect_ratio_info_present_flag : 1 aspect_ratio_idc : 1 sar_width : 0 sar_height : 0 overscan_info_present_flag : 0 overscan_appropriate_flag : 0 video_signal_type_present_flag : 1 video_format : 5 video_full_range_flag : 1 colour_description_present_flag : 0 colour_primaries : 0 transfer_characteristics : 0 matrix_coefficients : 0 chroma_loc_info_present_flag : 0 chroma_sample_loc_type_top_field : 0 chroma_sample_loc_type_bottom_field : 0 timing_info_present_flag : 1 num_units_in_tick : 1 time_scale : 25 fixed_frame_rate_flag : 0 nal_hrd_parameters_present_flag : 0 vcl_hrd_parameters_present_flag : 0 low_delay_hrd_flag : 0 pic_struct_present_flag : 0 bitstream_restriction_flag : 1 motion_vectors_over_pic_boundaries_flag : 1 max_bytes_per_pic_denom : 0 max_bits_per_mb_denom : 0 log2_max_mv_length_horizontal : 6 log2_max_mv_length_vertical : 6 num_reorder_frames : 0 max_dec_frame_buffering : 1 === HRD === cpb_cnt_minus1 : 0 bit_rate_scale : 0 cpb_size_scale : 0 initial_cpb_removal_delay_length_minus1 : 0 cpb_removal_delay_length_minus1 : 0 dpb_output_delay_length_minus1 : 0 time_offset_length : 0 !! Found NAL at offset 695290 (0xA9BFA), size 4 (0x0004) ==================== NAL ==================== forbidden_zero_bit : 0 nal_ref_idc : 1 nal_unit_type : 8 ( Picture parameter set ) ======= PPS ======= pic_parameter_set_id : 0 seq_parameter_set_id : 0 entropy_coding_mode_flag : 0 pic_order_present_flag : 0 num_slice_groups_minus1 : 0 slice_group_map_type : 0 num_ref_idx_l0_active_minus1 : 0 num_ref_idx_l1_active_minus1 : 0 weighted_pred_flag : 0 weighted_bipred_idc : 0 pic_init_qp_minus26 : 3 pic_init_qs_minus26 : 0 chroma_qp_index_offset : 0 deblocking_filter_control_present_flag : 1 constrained_intra_pred_flag : 0 redundant_pic_cnt_present_flag : 0 transform_8x8_mode_flag : 1 pic_scaling_matrix_present_flag : 0 second_chroma_qp_index_offset : 1 !! Found NAL at offset 695297 (0xA9C01), size 50725 (0xC625) ==================== NAL ==================== forbidden_zero_bit : 0 nal_ref_idc : 1 nal_unit_type : 5 ( Coded slice of an IDR picture ) ======= Slice Header ======= first_mb_in_slice : 0 slice_type : 2 ( I slice ) pic_parameter_set_id : 0 frame_num : 0 field_pic_flag : 0 bottom_field_flag : 0 idr_pic_id : 0 pic_order_cnt_lsb : 0 delta_pic_order_cnt_bottom : 0 redundant_pic_cnt : 0 direct_spatial_mv_pred_flag : 0 num_ref_idx_active_override_flag : 0 num_ref_idx_l0_active_minus1 : 0 num_ref_idx_l1_active_minus1 : 0 cabac_init_idc : 0 slice_qp_delta : 5 sp_for_switch_flag : 0 slice_qs_delta : 0 disable_deblocking_filter_idc : 0 slice_alpha_c0_offset_div2 : 0 slice_beta_offset_div2 : 0 slice_group_change_cycle : 0 === Prediction Weight Table === luma_log2_weight_denom : 0 chroma_log2_weight_denom : 0 luma_weight_l0_flag : 0 chroma_weight_l0_flag : 0 luma_weight_l1_flag : 0 chroma_weight_l1_flag : 0 === Ref Pic List Reordering === ref_pic_list_reordering_flag_l0 : 0 ref_pic_list_reordering_flag_l1 : 0 === Decoded Ref Pic Marking === no_output_of_prior_pics_flag : 0 long_term_reference_flag : 0 adaptive_ref_pic_marking_mode_flag : 0 !! Found NAL at offset 746025 (0xB6229), size 38612 (0x96D4) ==================== NAL ==================== forbidden_zero_bit : 0 nal_ref_idc : 1 nal_unit_type : 5 ( Coded slice of an IDR picture ) ======= Slice Header ======= first_mb_in_slice : 1840 slice_type : 2 ( I slice ) pic_parameter_set_id : 0 frame_num : 0 field_pic_flag : 0 bottom_field_flag : 0 idr_pic_id : 0 pic_order_cnt_lsb : 0 delta_pic_order_cnt_bottom : 0 redundant_pic_cnt : 0 direct_spatial_mv_pred_flag : 0 num_ref_idx_active_override_flag : 0 num_ref_idx_l0_active_minus1 : 0 num_ref_idx_l1_active_minus1 : 0 cabac_init_idc : 0 slice_qp_delta : 5 sp_for_switch_flag : 0 slice_qs_delta : 0 disable_deblocking_filter_idc : 0 slice_alpha_c0_offset_div2 : 0 slice_beta_offset_div2 : 0 slice_group_change_cycle : 0 === Prediction Weight Table === luma_log2_weight_denom : 0 chroma_log2_weight_denom : 0 luma_weight_l0_flag : 0 chroma_weight_l0_flag : 0 luma_weight_l1_flag : 0 chroma_weight_l1_flag : 0 === Ref Pic List Reordering === ref_pic_list_reordering_flag_l0 : 0 ref_pic_list_reordering_flag_l1 : 0 === Decoded Ref Pic Marking === no_output_of_prior_pics_flag : 0 long_term_reference_flag : 0 adaptive_ref_pic_marking_mode_flag : 0
Both I slices show the frame_num = 0. The next 2 (not shown) have frame_num = 1.
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Getting realtime output from ffmpeg to be used in progress bar (PyQt4, stdout)
8 mars 2017, par Jason O'NeilI’ve looked at a number of questions but still can’t quite figure this out. I’m using PyQt, and am hoping to run
ffmpeg -i file.mp4 file.avi
and get the output as it streams so I can create a progress bar.I’ve looked at these questions :
Can ffmpeg show a progress bar ?
http://stackoverflow.com/questions/1606795/catching-stdout-in-realtime-from-subprocessI’m able to see the output of a rsync command, using this code :
import subprocess, time, os, sys
cmd = "rsync -vaz -P source/ dest/"
p, line = True, 'start'
p = subprocess.Popen(cmd,
shell=True,
bufsize=64,
stdin=subprocess.PIPE,
stderr=subprocess.PIPE,
stdout=subprocess.PIPE)
for line in p.stdout:
print("OUTPUT>>> " + str(line.rstrip()))
p.stdout.flush()But when I change the command to
ffmpeg -i file.mp4 file.avi
I receive no output. I’m guessing this has something to do with stdout / output buffering, but I’m stuck as to how to read the line that looks likeframe= 51 fps= 27 q=31.0 Lsize= 769kB time=2.04 bitrate=3092.8kbits/s
Which I could use to figure out progress.
Can someone show me an example of how to get this info from ffmpeg into python, with or without the use of PyQt (if possible)
EDIT :
I ended up going with jlp’s solution, my code looked like this :#!/usr/bin/python
import pexpect
cmd = 'ffmpeg -i file.MTS file.avi'
thread = pexpect.spawn(cmd)
print "started %s" % cmd
cpl = thread.compile_pattern_list([
pexpect.EOF,
"frame= *\d+",
'(.+)'
])
while True:
i = thread.expect_list(cpl, timeout=None)
if i == 0: # EOF
print "the sub process exited"
break
elif i == 1:
frame_number = thread.match.group(0)
print frame_number
thread.close
elif i == 2:
#unknown_line = thread.match.group(0)
#print unknown_line
passWhich gives this output :
started ffmpeg -i file.MTS file.avi
frame= 13
frame= 31
frame= 48
frame= 64
frame= 80
frame= 97
frame= 115
frame= 133
frame= 152
frame= 170
frame= 188
frame= 205
frame= 220
frame= 226
the sub process exitedPerfect !
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opencv + opengl + ffmpeg ?
4 août 2012, par JeiKeiI'm trying to write a application that uses ffmpeg to play a video, opencv to analysis camera input data and opengl to show UI.
The reason I want to use openGL is because opencv does not support transparent images for UI, also opencv does not support playing sound of a video.
is there any tutorial for this ?