Download Fragmented Video Stream ~UPD~

I'm building an application that requires playback of a video on disk while being encoded by FFMPEG (in other words, psuedostreaming to disk - playback trails just behind of the encode like in a live stream). So the MOOV atom essentially needs to be generated as its being processed (or interleaved into the stream in chunks), and I've tried using empty_moov with no luck (especially since quicktime doesn't support it).

Fragmented MP4 is the way to do it, but it uses the empty_moov.Regular MP4 files have their header at the end (and not the beginning like fMP4), when everything is already known. It isn't meant for streaming.

Download Fragmented Video Stream

Download File 🔥 https://shurll.com/2y2QjI 🔥

I can see that using ffprobe that there is a Duration parameter, but this appears to show the up time of the linear stream ie hours mins secs, but what I need is the fragments duration in seconds and milliseconds.

Habitat fragmentation impedes dispersal of aquatic fauna, and barrier removal is increasingly used to increase stream network connectivity and facilitate fish dispersal. Improved understanding of fish community response to barrier removal is needed, especially in fragmented agricultural streams where numerous antiquated dams are likely destined for removal. We examined post-removal responses in two distinct fish communities formerly separated by a small aging mill dam. The dam was removed midway through the 6 year study, enabling passage for downstream fishes affiliated with a connected reservoir into previously inaccessible habitat, thus creating the potential for taxonomic homogenization between upstream and downstream communities. Both communities changed substantially post-removal. Two previously excluded species (white sucker, yellow perch) established substantial populations upstream of the former dam, contributing to a doubling of total fish biomass. Meanwhile, numerical density of pre-existing upstream fishes declined. Downstream, largemouth bass density was inversely correlated with prey fish density throughout the study, while post-removal declines in bluegill density coincided with cooler water temperature and increased suspended and benthic fine sediment. Upstream and downstream fish communities became more similar post-removal, represented by a shift in Bray-Curtis index from 14 to 41 % similarity. Our findings emphasize that barrier removal in highly fragmented stream networks can facilitate the unintended and possibly undesirable spread of species into headwater streams, including dispersal of species from remaining reservoirs. We suggest that knowledge of dispersal patterns for key piscivore and competitor species in both the target system and neighboring systems may help predict community outcomes following barrier removal.

We extend our gratitude to Bill Ginsler, Mark Knudsen, and Larry Hamele for providing access to the study site and background information on the stream history and fish community. We also thank Emily Stanley, Helen Sarakinos, and the River Alliance of Wisconsin for support throughout the study, Christopher Patrick for input on community similarity analysis, and several anonymous reviewers for helpful critiques. We appreciate field and laboratory assistance provided by Olaf Jensen, Jereme Gaeta, Stephen Klobucar, Lee Zinn, Kyle Amend, Chase Brossard, James Hardy, Robert Johnson, Page Mieritz, Aliya Rubinstein, and Gabrielle Lehrer-Brey. We also thank USGS-Water Sciences for loaned equipment. This project was funded by an NSF RAPID grant to James Kitchell (grant number DEB-0935710), and by the University of Wisconsin Center for Limnology CAPEX program. Mention of trade names is for descriptive purpose only and does not constitute endorsement or recommendation of their use by the U.S. government. This study is contribution number 1890 to the USGS, Great Lakes Science Center.

Aims. We investigate the origin of UV and X-ray emission at impact regions of density structured (fragmented) accretion streams. We study if and how the stream fragmentation and the resulting structure of the post-shock region determine the observed profiles of UV and X-ray emission lines.

More recently 2D MHD models of accretion impacts have been studied (Orlando et al. 2010, 2013; Matsakos et al. 2013) to explore those cases where the low-tag_hash_108 approximation cannot be applied (and, therefore, the 1D models cannot be used). These models have shown that the accretion dynamics can be complex with the structure and stability of the impact region of the stream strongly depending on the configuration and strength of the stellar magnetic field. Depending on the magnetic field strength, the atmosphere around the impact region can be also perturbed, leading to accreting plasma leaks at the border of the main stream.

The model describes a fragmented accretion stream impacting the surface of a CTTS. We assume that the accretion occurs along magnetic field lines that link the circumstellar disk to the surface of the star, and that the accretion stream is not continuous but is composed of blobs with different density.

Our model takes into account the stellar magnetic field, gravity, radiative cooling from optically thin plasma and thermal conduction, including the effects of heat flux saturation. The impact of the accretion stream is modeled by solving the time-dependent MHD equations: where tag_hash_109 is the density, v is the plasma velocity, m = tag_hash_112v is the momentum in volume unit, B is the magnetic field, pt = p + B2/ 2 is the total pressure (magnetic and thermal), E is the total energy density (), g is the gravity, Fc is the conductive flux, n is the plasma density; (T) represents the optically thin radiative losses per unit emission measure derived with the PINTofALE (Kashyap & Drake 2000) spectral code with the CHIANTI atomic lines database (Landi et al. 2013) using solar abundances.

In addition to the simulations describing the impact of a train of blobs, we performed simulations describing the more general case of a falling series of circular fragments (blobs) with a random spatial distribution. We assumed the stream consisting of a column with density 109 cm-3 and a series of blobs with random values of density ranging between 5 1010 cm-3 and 5 1011 cm-3. For the runs Frag-N20 and Frag-N55 Table 1 reports the number of blobs described in the initial conditions (Nbl). For these simulations we adopted a Cartesian coordinate system and solved the MHD equations in the plane (x,y). These simulations are analogous to those presented by Reale et al. (2014) except for the presence of the stellar magnetic field which we considered here. This allowed us to compare our results with those presented in Reale et al. (2014) and to evaluate the role of the magnetic field in determining the structure of the post-shock plasma.

Fig. 3Color maps in log scale of evolution of density (left half-panel) and temperature (right half-panel) of plasma for the general case of fragmented stream (run Frag-55 in Table 1). White lines represent magnetic field lines.

The more general case of a randomly fragmented stream was investigated through simulations describing a column with uniform density of 109 cm-3 and a series of circular blobs with random spatial distribution and random density in the range 5 1010 and 5 1011 cm-3.

In these simulations, the blob impacts reproduce all the cases explored assuming a train of blobs and, in addition, consider the interaction of multiple shocks with downfalling fragments. We performed two simulations assuming the same mass accretion rate but with different granularity of stream fragmentation: run Frag-N20 considers 20 blobs with radius ranging between 3.48 108 cm and 1.39 109 cm (coarse fragmentation), and run Frag-N55 considers 55 blobs with radius ranging between 3.48 108 cm and 6.96 108 cm (fine fragmentation).

The evolution is similar in the two cases. As for the train of blobs (see Sect. 3.1), the first blobs impact onto the chromosphere and produce upflowing surges of post-shock plasma that expand through the interblob medium (see Fig. 3 and on-line movie). The expansion ends when the surges hit the following falling blobs. At variance with the case of a train of blobs, the interactions of the surges with the falling blobs occur at different altitudes due to the initial random positions of the blobs in the stream. As a result, the structure of the post-shock region is very complex and consists of several knots and filaments of shock-heated plasma with a broad range of velocities, densities, and temperatures (see Fig. 3). The two runs Frag-N20 and Frag-N55 differ mainly for the average extension of the post-shock region. In fact, in run Frag-N20 the average distance among the blobs is larger than that in run Frag-N55. As a consequence, the surges have more time to expand upwards, so that their interactions with the downfalling blobs occur, on average, at higher altitudes. Because of this longer expansion, we also expect that a plasma component contributing to a blue shift of emission lines (namely that due to the upflowing surges) would be more important in run Frag-N20 than in run Frag-N55.

Our case of a randomly fragmented stream is similar to the HD model developed by Reale et al. (2014). The main differences are that the Reale et al. model neglects the magnetic field and consider blobs without a perfectly vertical trajectory with respect to the chromosphere. As a result, in the case explored by Reale et al. (2014), the plasma dynamics is not influenced by the magnetic field lines and the small deviation from the vertical trajectory determines an asymmetric evolution of the post-shock plasma. The surges that bounce back are not confined by the magnetic field and are free to expand upward and laterally, causing a more efficient adiabatic cooling of the plasma and a lower upflowing velocity. Also the inclined trajectory of the blobs causes the surges to develop preferentially in a direction opposite from that of arrival of the blobs. For all of these reasons the post-shock region is very complex and is characterized by a wide range of velocities of the shocked plasma. ff782bc1db