ret = kd_mp4_get_frame(handle, frame_data)取得数据后做什么??
如何解码??如何输出到屏幕??
ret = kd_mp4_get_frame(handle, frame_data)取得数据后做什么??
如何解码??如何输出到屏幕??
您好,kd_mp4_get_frame返回的是经过编码的264数据流。详细的解码显示流程请参阅“H264/H265解码章节”中的示例。
您也可以参照以下示例:
# MP4 Demuxer Example
#
# This script demuxes an MP4 file, extracting video and audio streams.
# Supported video codecs: H.264, H.265
# Supported audio codecs: G.711A, G.711U
from media.media import *
from mpp.mp4_format import *
from mpp.mp4_format_struct import *
from media.pyaudio import *
import media.g711 as g711
from mpp.payload_struct import *
import media.vdecoder as vdecoder
from media.display import *
import uctypes
import time
import _thread
import os
from media.display import *
def demuxer_mp4(filename,vdec):
mp4_cfg = k_mp4_config_s()
video_info = k_mp4_video_info_s()
video_track = False
audio_info = k_mp4_audio_info_s()
audio_track = False
mp4_handle = k_u64_ptr()
mp4_cfg.config_type = K_MP4_CONFIG_DEMUXER
mp4_cfg.muxer_config.file_name[:] = bytes(filename, 'utf-8')
mp4_cfg.muxer_config.fmp4_flag = 0
ret = kd_mp4_create(mp4_handle, mp4_cfg)
if ret:
raise OSError("kd_mp4_create failed:",filename)
file_info = k_mp4_file_info_s()
kd_mp4_get_file_info(mp4_handle.value, file_info)
#print("=====file_info: track_num:",file_info.track_num,"duration:",file_info.duration)
for i in range(file_info.track_num):
track_info = k_mp4_track_info_s()
ret = kd_mp4_get_track_by_index(mp4_handle.value, i, track_info)
if (ret < 0):
raise ValueError("kd_mp4_get_track_by_index failed")
if (track_info.track_type == K_MP4_STREAM_VIDEO):
if (track_info.video_info.codec_id == K_MP4_CODEC_ID_H264 or track_info.video_info.codec_id == K_MP4_CODEC_ID_H265):
video_track = True
video_info = track_info.video_info
print(" codec_id: ", video_info.codec_id)
print(" track_id: ", video_info.track_id)
print(" width: ", video_info.width)
print(" height: ", video_info.height)
else:
print("video not support codecid:",track_info.video_info.codec_id)
elif (track_info.track_type == K_MP4_STREAM_AUDIO):
if (track_info.audio_info.codec_id == K_MP4_CODEC_ID_G711A or track_info.audio_info.codec_id == K_MP4_CODEC_ID_G711U):
audio_track = True
audio_info = track_info.audio_info
print(" codec_id: ", audio_info.codec_id)
print(" track_id: ", audio_info.track_id)
print(" channels: ", audio_info.channels)
print(" sample_rate: ", audio_info.sample_rate)
print(" bit_per_sample: ", audio_info.bit_per_sample)
#audio_info.channels = 2
else:
print("audio not support codecid:",track_info.audio_info.codec_id)
if (video_track == False):
raise ValueError("video track not found")
# 记录初始系统时间
start_system_time = time.ticks_ms()
# 记录初始视频时间戳
start_video_timestamp = 0
while (True):
frame_data = k_mp4_frame_data_s()
ret = kd_mp4_get_frame(mp4_handle.value, frame_data)
if (ret < 0):
raise OSError("get frame data failed")
if (frame_data.eof):
break
if (frame_data.codec_id == K_MP4_CODEC_ID_H264 or frame_data.codec_id == K_MP4_CODEC_ID_H265):
data = uctypes.bytes_at(frame_data.data,frame_data.data_length)
vdec.decode(data)
print("video frame_data.codec_id:",frame_data.codec_id,"data_length:",frame_data.data_length,"timestamp:",frame_data.time_stamp)
# 计算视频时间戳经历的时长
video_timestamp_elapsed = frame_data.time_stamp - start_video_timestamp
# 计算系统时间戳经历的时长
current_system_time = time.ticks_ms()
system_time_elapsed = current_system_time - start_system_time
# 如果系统时间戳经历的时长小于视频时间戳经历的时长,进行延时
if system_time_elapsed < video_timestamp_elapsed:
time.sleep_ms(video_timestamp_elapsed - system_time_elapsed)
elif(frame_data.codec_id == K_MP4_CODEC_ID_G711A or frame_data.codec_id == K_MP4_CODEC_ID_G711U):
data = uctypes.bytes_at(frame_data.data,frame_data.data_length)
print("audio frame_data.codec_id:",frame_data.codec_id,"data_length:",frame_data.data_length,"timestamp:",frame_data.time_stamp)
kd_mp4_destroy(mp4_handle.value)
if __name__ == "__main__":
os.exitpoint(os.EXITPOINT_ENABLE)
Display.init(Display.ST7701,to_ide=True)
vdec = vdecoder.Decoder(K_PT_H264)
MediaManager.init()
vdec.create()
bind_info = vdec.bind_info(width=ALIGN_UP(800, 16),height=480,chn=vdec.get_vdec_channel())
Display.bind_layer(**bind_info, layer = Display.LAYER_VIDEO1)
vdec.start()
demuxer_mp4("/sdcard/test_1.mp4",vdec)
vdec.stop()
# 销毁video decoder
vdec.destroy()
time.sleep(1)
Display.deinit()
time.sleep_ms(50)
MediaManager.deinit()