Another question about missing audio

I have an mpeg file which plays without sound using the WDTV. I can
run it through ffmpeg and get a version which has audio; however, as I
have a number of these files, I’d rather not if I can avoid it. Based
on the mediainfo output, should it work?

ffmpeg line to “fix”:

 time ffmpeg -i Prep_For_Sale.mpg -acodec mp2 -vcodec copy testoutput.mpg

Here’s what mediainfo says about the original:

General
Complete name                    : Prep_For_Sale.mpg
Format                           : MPEG-PS
File size                        : 336 MiB
Duration                         : 3mn 6s
Overall bit rate                 : 15.1 Mbps

Video
ID                               : 224 (0xE0)
Format                           : MPEG Video
Format version                   : Version 2
Format profile                   : Main@High
Format settings, BVOP            : Yes
Format settings, Matrix          : Default
Duration                         : 3mn 6s
Bit rate mode                    : Variable
Bit rate                         : 14.4 Mbps
Nominal bit rate                 : 65.0 Mbps
Width                            : 1 920 pixels
Height                           : 1 080 pixels
Display aspect ratio             : 16:9
Frame rate                       : 29.970 fps
Color space                      : YUV
Chroma subsampling               : 4:2:0
Bit depth                        : 8 bits
Scan type                        : Interlaced
Scan order                       : Top Field First
Bits/(Pixel*Frame)               : 0.232
Stream size                      : 321 MiB (95%)

Audio
ID                               : 128 (0x80)
Format                           : AC-3
Format/Info                      : Audio Coding 3
Mode extension                   : CM (complete main)
Duration                         : 3mn 6s
Bit rate mode                    : Constant
Bit rate                         : 384 Kbps
Channel(s)                       : 2 channels
Channel positions                : Front: L R
Sampling rate                    : 48.0 KHz
Bit depth                        : 16 bits
Video delay                      : -205ms
Stream size                      : 8.55 MiB (3%)

Text
ID                               : 224 (0xE0)-608-1
Format                           : EIA-608
Muxing mode                      : MPEG Video / EIA-708
Muxing mode, more info           : Muxed in Video #1
Stream size                      : 0.00 Byte (0%)