6. Bitrate plots, Continued

Finally, Figures 8 and 9 show the results for the PSP/MPEG4 file.

Figure 8: PSP file play bitrate plot

Once again, average file play and stream rates were about equal and the peak stream rate was lower than the play rate by a little more than 10%. Peak to average rate ratios were 2.8 for file play and 2.2 for streaming.

Figure 9: PSP file stream bitrate plot

Since the same content was not used in each case, the ratios and percentages described above can't be used to compare the encoding methods used. They are provided only to show how a single number for bit rate can't begin to capture the network load a multimedia file presents.

I originally also included Quicktime 7 HD files encoded in H.264, but had to give up on using them in the test. The VLC player's H.264 support is still "experimental" (see this chart) and I did, in fact have problems playing various files from Apple's movie trailer site. And using the Quicktime player itself was out, since I couldn't get it to open a stream from the VLC player.