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Diffstat (limited to 'gst-libs/ext/mplex/bits.cc')
| -rw-r--r-- | gst-libs/ext/mplex/bits.cc | 358 |
1 files changed, 0 insertions, 358 deletions
diff --git a/gst-libs/ext/mplex/bits.cc b/gst-libs/ext/mplex/bits.cc deleted file mode 100644 index 84d05919..00000000 --- a/gst-libs/ext/mplex/bits.cc +++ /dev/null @@ -1,358 +0,0 @@ -/** @file bits.cc, bit-level output */ - -/* Copyright (C) 2001, Andrew Stevens <andrew.stevens@philips.com> * - - * - * Disclaimer of Warranty - * - * These software programs are available to the user without any license fee or - * royalty on an "as is" basis. The MPEG Software Simulation Group disclaims - * any and all warranties, whether express, implied, or statuary, including any - * implied warranties or merchantability or of fitness for a particular - * purpose. In no event shall the copyright-holder be liable for any - * incidental, punitive, or consequential damages of any kind whatsoever - * arising from the use of these programs. - * - * This disclaimer of warranty extends to the user of these programs and user's - * customers, employees, agents, transferees, successors, and assigns. - * - * The MPEG Software Simulation Group does not represent or warrant that the - * programs furnished hereunder are free of infringement of any third-party - * patents. - * - * Commercial implementations of MPEG-1 and MPEG-2 video, including shareware, - * are subject to royalty fees to patent holders. Many of these patents are - * general enough such that they are unavoidable regardless of implementation - * design. - * - */ - -#include <config.h> -#include <stdlib.h> -#include <errno.h> -#include <string.h> -#include <sys/param.h> -#include <assert.h> -#include "mjpeg_logging.h" -#include "bits.hh" - - -/// Initializes the bitstream, sets internal variables. -// TODO: The buffer size should be set dynamically to sensible sizes. -// -BitStream::BitStream (): -user_data (NULL) -{ - totbits = 0LL; - buffer_start = 0LL; - eobs = true; - readpos = 0LL; - bfr = 0; - bfr_size = 0; -} - -/// Deconstructor. Deletes the internal buffer. -BitStream::~BitStream () -{ - delete bfr; -} - -/** - Refills an IBitStream's input buffer based on the internal variables bufcount and bfr_size. - */ -bool -IBitStream::refill_buffer () -{ - size_t i; - - if (bufcount >= bfr_size) { - SetBufSize (bfr_size + 4096); - } - - i = read_callback (this, bfr + bufcount, static_cast < size_t > (bfr_size - bufcount), user_data); - bufcount += i; - - if (i == 0) { - eobs = true; - return false; - } - return true; -} - -/** - Flushes all read input up-to *but not including* bit - unbuffer_upto. -@param flush_to the number of bits to flush -*/ - -void -IBitStream::flush (bitcount_t flush_upto) -{ - if (flush_upto > buffer_start + bufcount) - mjpeg_error_exit1 ("INTERNAL ERROR: attempt to flush input beyond buffered amount"); - - if (flush_upto < buffer_start) - mjpeg_error_exit1 - ("INTERNAL ERROR: attempt to flush input stream before first buffered byte %d last is %d", - (int) flush_upto, (int) buffer_start); - unsigned int bytes_to_flush = static_cast < unsigned int >(flush_upto - buffer_start); - - // - // Don't bother actually flushing until a good fraction of a buffer - // will be cleared. - // - - if (bytes_to_flush < bfr_size * 3 / 4) - return; - - bufcount -= bytes_to_flush; - buffer_start = flush_upto; - byteidx -= bytes_to_flush; - memmove (bfr, bfr + bytes_to_flush, static_cast < size_t > (bufcount)); -} - - -/** - Undo scanning / reading - N.b buffer *must not* be flushed between prepareundo and undochanges. - @param undo handle to store the undo information -*/ -void -IBitStream::prepareundo (BitStreamUndo & undo) -{ - undo = *(static_cast < BitStreamUndo * >(this)); -} - -/** -Undoes changes committed to an IBitStream. -@param undo handle to retrieve the undo information - */ -void -IBitStream::undochanges (BitStreamUndo & undo) -{ - *(static_cast < BitStreamUndo * >(this)) = undo; -} - -/** - Read a number bytes over an IBitStream, using the buffer. - @param dst buffer to read to - @param length the number of bytes to read - */ -unsigned int -IBitStream::read_buffered_bytes (uint8_t * dst, unsigned int length) -{ - unsigned int to_read = length; - - if (readpos < buffer_start) - mjpeg_error_exit1 - ("INTERNAL ERROR: access to input stream buffer @ %d: before first buffered byte (%d)", - (int) readpos, (int) buffer_start); - - if (readpos + length > buffer_start + bufcount) { - /* - if (!feof (fileh)) { - mjpeg_error - ("INTERNAL ERROR: access to input stream buffer beyond last buffered byte @POS=%lld END=%d REQ=%lld + %d bytes", - readpos, bufcount, readpos - (bitcount_t) buffer_start, length); - abort (); - } - */ - to_read = static_cast < unsigned int >((buffer_start + bufcount) - readpos); - } - memcpy (dst, bfr + (static_cast < unsigned int >(readpos - buffer_start)), to_read); - // We only ever flush up to the start of a read as we - // have only scanned up to a header *beginning* a block that is then - // read - flush (readpos); - readpos += to_read; - return to_read; -} - -/** open the device to read the bit stream from it -@param bs_filename filename to open -@param buf_size size of the internal buffer -*/ -void -IBitStream::open (ReadCallback read_callback, void *user_data, unsigned int buf_size) -{ - this->read_callback = read_callback; - this->user_data = user_data; - - bfr_size = buf_size; - if (bfr == NULL) - bfr = new uint8_t[buf_size]; - else { - delete bfr; - - bfr = new uint8_t[buf_size]; - } - - byteidx = 0; - bitidx = 8; - totbits = 0LL; - bufcount = 0; - eobs = false; - if (!refill_buffer ()) { - if (bufcount == 0) { - mjpeg_error_exit1 ("Unable to read."); - } - } -} - - -/** sets the internal buffer size. - @param new_buf_size the new internal buffer size -*/ -void -IBitStream::SetBufSize (unsigned int new_buf_size) -{ - assert (bfr != NULL); // Must be open first! - assert (new_buf_size >= bfr_size); // Can only be increased in size... - - if (bfr_size != new_buf_size) { - uint8_t *new_buf = new uint8_t[new_buf_size]; - - memcpy (new_buf, bfr, static_cast < size_t > (bfr_size)); - delete bfr; - - bfr_size = new_buf_size; - bfr = new_buf; - } - -} - -/** - close the device containing the bit stream after a read process -*/ -void -IBitStream::close () -{ -} - - -// TODO replace with shift ops! - -uint8_t - IBitStream::masks[8] = { - 0x1, - 0x2, - 0x4, - 0x8, - 0x10, - 0x20, - 0x40, -0x80 }; - -/*read 1 bit from the bit stream -@returns the read bit, 0 on EOF */ -uint32_t -IBitStream::get1bit () -{ - unsigned int bit; - - if (eobs) - return 0; - - bit = (bfr[byteidx] & masks[bitidx - 1]) >> (bitidx - 1); - totbits++; - bitidx--; - if (!bitidx) { - bitidx = 8; - byteidx++; - if (byteidx == bufcount) { - refill_buffer (); - } - } - - return bit; -} - -/*read N bits from the bit stream -@returns the read bits, 0 on EOF */ -uint32_t -IBitStream::getbits (int N) -{ - uint32_t val = 0; - int i = N; - unsigned int j; - - // Optimize: we are on byte boundary and want to read multiple of bytes! - if ((bitidx == 8) && ((N & 7) == 0)) { - i = N >> 3; - while (i > 0) { - if (eobs) - return 0; - val = (val << 8) | bfr[byteidx]; - byteidx++; - totbits += 8; - if (byteidx == bufcount) { - refill_buffer (); - } - i--; - } - } else { - while (i > 0) { - if (eobs) - return 0; - - j = (bfr[byteidx] & masks[bitidx - 1]) >> (bitidx - 1); - totbits++; - bitidx--; - if (!bitidx) { - bitidx = 8; - byteidx++; - if (byteidx == bufcount) { - refill_buffer (); - } - } - val = (val << 1) | j; - i--; - } - } - return val; -} - - -/** This function seeks for a byte aligned sync word (max 32 bits) in the bit stream and - places the bit stream pointer right after the sync. - This function returns 1 if the sync was found otherwise it returns 0 -@param sync the sync word to search for -@param N the number of bits to retrieve -@param lim number of bytes to search through -@returns false on error */ - -bool -IBitStream::seek_sync (uint32_t sync, int N, int lim) -{ - uint32_t val, val1; - uint32_t maxi = ((1U << N) - 1); /* pow(2.0, (double)N) - 1 */ ; - if (maxi == 0) { - maxi = 0xffffffff; - } - while (bitidx != 8) { - get1bit (); - } - - val = getbits (N); - if (eobs) - return false; - while ((val & maxi) != sync && --lim) { - val <<= 8; - val1 = getbits (8); - val |= val1; - if (eobs) - return false; - } - - return (!!lim); -} - - - -/* - * Local variables: - * c-file-style: "stroustrup" - * tab-width: 4 - * indent-tabs-mode: nil - * End: - */ |