--- /dev/null
+#include "../libzmpeg3.h"
+
+static void
+toc_error()
+{
+ zerr( "frame accurate seeking without a table of contents \n"
+ "is no longer supported. Use mpeg3toc <mpeg file> <table of contents>\n"
+ "to generate a table of contents and load the table of contents instead.\n");
+}
+
+void zvideo_t::
+cache_frame()
+{
+ if( output_src[0] ) {
+ int coded_size = coded_picture_width * coded_picture_height;
+ int chrom_size = chrom_width * chrom_height;
+ track->frame_cache->put_frame(framenum-1,
+ output_src[0], output_src[1], output_src[2],
+ coded_size, chrom_size, chrom_size);
+ }
+}
+
+int zvideo_t::
+drop_frames(long frames, int cache_it)
+{
+ int result = 0;
+ long frame_number = framenum + frames;
+//zmsgs("drop frames framenum %d frames %ld\n", framenum, frames);
+
+/* Read the selected number of frames and skip b-frames */
+ while(!result && frame_number > framenum ) {
+ if( cache_it ) {
+ result = read_frame_backend(0);
+ if( !result && ref_frames > 1 )
+ cache_frame();
+ }
+ else {
+//zmsgs("framenum %d frame_offset "_LX" last_packet_start "_LX" repeat %d/%d",
+// framenum,track->frame_offsets[framenum+1],vstream->demuxer->last_packet_start,
+// repeat_fields, current_field);
+ result = read_frame_backend(frame_number - framenum);
+//zmsgs(" type %c\n","XIPBD"[pict_type]);
+ }
+ }
+
+ return result;
+}
+
+int zbits_t::
+next_start_code()
+{
+//zmsg("1\n");
+ /* search forwards */
+ prev_byte_align();
+ int64_t stream_end = demuxer->stream_end;
+ if( demuxer->src->is_transport_stream() )
+ demuxer->stream_end = demuxer->program_byte + MAX_TS_PROBE;
+ else if( demuxer->src->is_program_stream() )
+ demuxer->stream_end = demuxer->program_byte + MAX_PGM_PROBE;
+ int zcode = -1, result = -1;
+
+ while( !eof() ) {
+ int bits = (uint8_t)zcode!=0 ? 24 : 8;
+ zcode = (zcode<<bits) | get_bits_noptr(bits);
+ if( (zcode&0xffffff) == PACKET_START_CODE_PREFIX ) {
+ zcode = (zcode<<8) + get_byte_noptr();
+ reset(result = zcode);
+//zmsgs("5 %04x\n",zcode);
+ break;
+ }
+ }
+
+ demuxer->stream_end = stream_end;
+ return result;
+}
+
+/* Line up on the beginning of the next code. */
+int zbits_t::
+next_code(uint32_t zcode)
+{
+ while(!eof() && show_bits_noptr(32) != zcode ) {
+ get_byte_noptr();
+ }
+ return eof();
+}
+
+/* Line up on the beginning of the previous code. */
+int zdemuxer_t::
+prev_code(uint32_t zcode)
+{
+ uint32_t current_code = 0;
+#define PREV_CODE_MACRO { current_code >>= 8; \
+ current_code |= ((uint32_t)read_prev_char()) << 24; }
+
+ PREV_CODE_MACRO
+ PREV_CODE_MACRO
+ PREV_CODE_MACRO
+ PREV_CODE_MACRO
+
+ while( !bof() && current_code != zcode ) {
+ PREV_CODE_MACRO
+ }
+ return bof();
+}
+
+int zvideo_t::
+seek_byte(int64_t byte)
+{
+ byte_seek = byte;
+ return 0;
+}
+
+int zvideo_t::
+seek_frame(long frame)
+{
+ frame_seek = frame;
+ return 0;
+}
+
+int zvideo_t::
+rewind_video(int preload)
+{
+ vstream->reset();
+ framenum = 0;
+ if( track->frame_offsets )
+ vstream->seek_byte(track->frame_offsets[0]);
+ else
+ vstream->seek_byte(0);
+ track->reset_pts();
+ repeat_data = ref_frames = 0;
+ last_number = framenum = -1;
+ return preload ? read_frame_backend(0) : 0;
+}
+
+int zvideo_t::
+seek()
+{
+ int result = 0;
+ int64_t byte;
+ long frame_number;
+ int debug = 0;
+ demuxer_t *demux = vstream->demuxer;
+
+/* Must do seeking here so files which don't use video don't seek. */
+/* Seeking is done in the demuxer */
+/* Seek to absolute byte */
+ if( byte_seek >= 0 ) {
+ byte = byte_seek;
+ byte_seek = -1;
+ if( byte != demux->tell_byte() ) {
+ demux->seek_byte(byte);
+ track->reset_pts();
+ if( byte > 0 ) {
+ //zmsg("1\n");
+ demux->start_reverse();
+ //zmsgs("1 "_LD"\n", demux->tell_byte());
+ for( int i=0; i<2; ++i ) { /* Rewind 2 I-frames */
+ if( has_gops ?
+ demux->prev_code(GOP_START_CODE) :
+ demux->prev_code(SEQUENCE_START_CODE) ) break;
+ }
+ //zmsgs("2 "_LD"\n", demux->tell_byte());
+ demux->start_forward();
+ if( track->frame_offsets ) {
+ int64_t offset = demux->tell_byte();
+ for( int k=0; k<track->total_keyframe_numbers; ++k ) {
+ frame_number = track->keyframe_numbers[k];
+ if( track->frame_offsets[frame_number] >= offset ) {
+ /* first entry is special */
+ framenum = frame_number>0 ? frame_number-1 : 0;
+ break;
+ }
+ }
+ }
+ else {
+ /* framenum no longer accurate, clear subtitles */
+ reset_subtitles();
+ }
+ }
+ else { /* Read first frame */
+ rewind_video();
+ }
+ vstream->reset();
+ repeat_data = ref_frames = 0;
+ //zmsgs("4 "_LD"\n", demux->tell_byte());
+ while( !result && !demux->eof() && demux->tell_byte() < byte ) {
+ result = read_frame_backend(0);
+ }
+ }
+ }
+ else if( frame_seek >= 0 ) {
+ /* Seek to a frame number */
+ frame_number = frame_seek;
+ frame_seek = -1;
+ if( frame_number != framenum ) {
+ if( debug ) zmsgs("%d\n", __LINE__);
+ if( frame_number < 0 ) frame_number = 0;
+ if( frame_number > maxframe ) frame_number = maxframe;
+ if(debug) zmsgs("%d %ld %d\n", __LINE__, frame_number, framenum);
+ /* Seek to I frame in table of contents. */
+ /* Determine time between seek position and previous subtitle. */
+ /* Subtract time difference from subtitle display time. */
+ if( frame_number > 0 && track->frame_offsets ) {
+ if( debug ) zmsgs("%d\n", __LINE__);
+ track->frame_cache->reset();
+ if( debug ) zmsgs("%d\n", __LINE__);
+ if( frame_number < framenum ||
+ frame_number-framenum > SEEK_THRESHOLD ) {
+ int idx = track->find_keyframe_index(frame_number);
+ /* back up 2 I frames, data may reference old refframes */
+ if( --idx < 0 ) idx = 0;
+ idx = track->keyframe_numbers[idx];
+ byte = track->frame_offsets[idx];
+ /* maybe lots of frames in one block, move is to earliest frame */
+ while( idx > 0 && track->frame_offsets[idx-1] == byte ) --idx;
+ if( debug ) zmsgs("%ld idx=%d, byte="_LD"\n", frame_number,idx,byte);
+ framenum = idx-1;
+ vstream->seek_byte(byte);
+ track->reset_pts();
+ repeat_data = ref_frames = 0;
+ /* get the first I-frame. It does not count in the frame sequence */
+ /* phys order is IBBPBBPBB... presentation order is BBIBBPBB... */
+ result = read_frame_backend(0);
+ }
+ if( debug ) zmsgs("%d %ld %d\n", __LINE__,frame_number,framenum);
+ if( !result && frame_number > framenum ) {
+ /* Read up to current frame */
+ int n = frame_number - framenum;
+ result = drop_frames(n, n < MAX_CACHE_FRAMES ? 1 : 0);
+ if( debug ) zmsgs("%d\n", __LINE__);
+ }
+ }
+ else if( frame_number == 0 ) {
+ result = rewind_video();
+ }
+ else {
+ /* No support for seeking without table of contents */
+ toc_error();
+ result = 1;
+ }
+ }
+ }
+ else if( framenum < 0 ) { /* preload */
+ result = rewind_video(1);
+ }
+ else
+ return 0;
+
+ seek_time = 0;
+ return result;
+}
+
+int zvideo_t::
+previous_frame()
+{
+ int result = 0;
+ int64_t target_byte = 0;
+ demuxer_t *demux = vstream->demuxer;
+ if( demux->tell_byte() <= 0 ) return 1;
+ /* Get location of end of previous picture */
+ demux->start_reverse();
+ result = demux->prev_code(PICTURE_START_CODE);
+ if( !result ) result = demux->prev_code(PICTURE_START_CODE);
+ if( !result ) result = demux->prev_code(PICTURE_START_CODE);
+ if( !result ) target_byte = demux->tell_byte();
+ if( !result ) { /* Rewind 2 I-frames */
+ if( has_gops )
+ result = demux->prev_code(GOP_START_CODE);
+ else
+ result = demux->prev_code(SEQUENCE_START_CODE);
+ }
+
+ if( !result )
+ {
+ if( has_gops )
+ result = demux->prev_code(GOP_START_CODE);
+ else
+ result = demux->prev_code(SEQUENCE_START_CODE);
+ }
+
+ demux->start_forward();
+ vstream->reset();
+
+ result = 0; /* Read up to correct byte */
+ repeat_data = ref_frames = 0;
+ while( !result && !demux->eof() && demux->tell_byte() < target_byte ) {
+ result = read_frame_backend(0);
+ }
+ repeat_data = 0;
+
+ return 0;
+}
+
projects / goodguy / history.git / blobdiff