mirror
/
F5OEO-tstools
kopia lustrzana https://github.com/F5OEO/tstools
1
0
Forkuj 0
Kod Zgłoszenia Projekty Wydania Wiki Aktywność
F5OEO-tstools/h262.c

1205 wiersze
34 KiB
C
Czysty Wina Historia

This file contains invisible Unicode characters!

This file contains invisible Unicode characters that may be processed differently from what appears below. If your use case is intentional and legitimate, you can safely ignore this warning. Use the Escape button to reveal hidden characters.

/*
* Datastructures and prototypes for reading H.262 (MPEG-2) elementary streams.
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is the MPEG TS, PS and ES tools.
*
* The Initial Developer of the Original Code is Amino Communications Ltd.
* Portions created by the Initial Developer are Copyright (C) 2008
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Amino Communications Ltd, Swavesey, Cambridge UK
*
* ***** END LICENSE BLOCK *****
*/
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include "compat.h"
#include "h262_fns.h"
#include "es_fns.h"
#include "ts_fns.h"
#include "reverse_fns.h"
#include "misc_fns.h"
#define DEBUG_GET_NEXT_PICTURE 0
#define DEBUG_AFD 0
/*
* Print out information derived from the start code, to the given stream.
*
* Note that if a "SYSTEM START" code is reported, then the data is
* likely to be PES or Transport Stream data, not Elementary Stream.
*
* Similarly, if a "TRANSPORT STREAM sync byte" is reported, then
* the stream is probably Transport Stream.
*
* If the stream is *not* Elementary Stream data, then it is possible
* that some of the apparent start code prefixes are actually false
* detections.
*/
extern void print_h262_start_code_str(FILE *stream,
byte start_code)
{
byte number;
char *str = NULL;
switch (start_code)
{
// H.262 start codes
case 0x00: str = "Picture"; break;
case 0xB0: str = "Reserved"; break;
case 0xB1: str = "Reserved"; break;
case 0xB2: str = "User data"; break;
case 0xB3: str = "SEQUENCE HEADER"; break;
case 0xB4: str = "Sequence error"; break;
case 0xB5: str = "Extension start"; break;
case 0xB6: str = "Reserved"; break;
case 0xB7: str = "SEQUENCE END"; break;
case 0xB8: str = "Group start"; break;
// System start codes - 13818-1 p32 Table 2-18 stream_id
// If these occur, then we're seeing PES headers
// - maybe we're looking at transport stream data?
case 0xBC: str = "SYSTEM START: Program stream map"; break;
case 0xBD: str = "SYSTEM START: Private stream 1"; break;
case 0xBE: str = "SYSTEM START: Padding stream"; break;
case 0xBF: str = "SYSTEM START: Private stream 2"; break;
case 0xF0: str = "SYSTEM START: ECM stream"; break;
case 0xF1: str = "SYSTEM START: EMM stream"; break;
case 0xF2: str = "SYSTEM START: DSMCC stream"; break;
case 0xF3: str = "SYSTEM START: 13522 stream"; break;
case 0xF4: str = "SYSTEM START: H.222 A stream"; break;
case 0xF5: str = "SYSTEM START: H.222 B stream"; break;
case 0xF6: str = "SYSTEM START: H.222 C stream"; break;
case 0xF7: str = "SYSTEM START: H.222 D stream"; break;
case 0xF8: str = "SYSTEM START: H.222 E stream"; break;
case 0xF9: str = "SYSTEM START: Ancillary stream"; break;
case 0xFF: str = "SYSTEM START: Program stream directory"; break;
default: str = NULL; break;
}
if (str != NULL)
fprintf(stream,str);
else if (start_code == 0x47)
fprintf(stream,"TRANSPORT STREAM sync byte");
else if (start_code >= 0x01 && start_code <= 0xAF)
fprintf(stream,"Slice, vertical posn %d",start_code);
else if (start_code >= 0xC0 && start_code <=0xDF)
{
number = start_code & 0x1F;
fprintf(stream,"SYSTEM START: Audio stream %02x",number);
}
else if (start_code >= 0xE0 && start_code <= 0xEF)
{
number = start_code & 0x0F;
fprintf(stream,"SYSTEM START: Video stream %x",number);
}
else if (start_code >= 0xFC && start_code <= 0xFE)
fprintf(stream,"SYSTEM START: Reserved data stream");
else
fprintf(stream,"SYSTEM START: Unrecognised stream id");
}
/*
* Build a new MPEG2 item datastructure.
*
* Returns 0 if it succeeds, 1 if some error occurs.
*/
extern int build_h262_item(h262_item_p *item)
{
int err;
h262_item_p new = malloc(SIZEOF_H262_ITEM);
if (new == NULL)
{
fprintf(stderr,"### Unable to allocate MPEG2 item datastructure\n");
return 1;
}
err = setup_ES_unit(&(new->unit));
if (err)
{
fprintf(stderr,"### Unable to allocate MPEG2 item data buffer\n");
free(new);
return 1;
}
*item = new;
return 0;
}
/*
* Tidy up and free an MPEG2 item datastructure after we've finished with it.
*
* Empties the MPEG2 item datastructure, frees it, and sets `item` to NULL.
*
* If `item` is already NULL, does nothing.
*/
extern void free_h262_item(h262_item_p *item)
{
if (*item == NULL)
return;
clear_ES_unit(&(*item)->unit);
free(*item);
*item = NULL;
}
/*
* Print out useful information about this MPEG2 item, on the given stream.
*/
extern void report_h262_item(FILE *stream,
h262_item_p item)
{
fprintf(stream,OFFSET_T_FORMAT_08 "/%04d: MPEG2 item %02x (",
item->unit.start_posn.infile,
item->unit.start_posn.inpacket,item->unit.start_code);
print_h262_start_code_str(stream,item->unit.start_code);
fprintf(stream,")");
if (item->unit.start_code == 0)
fprintf(stream," %d (%s)",item->picture_coding_type,
H262_PICTURE_CODING_STR(item->picture_coding_type));
fprintf(stream," size %d",item->unit.data_len);
fprintf(stream,"\n");
}
// ------------------------------------------------------------
// MPEG2 item *data* stuff
// ------------------------------------------------------------
/*
* Find and read in the next MPEG2 item.
*
* Be careful if using this in conjunction with reading H.262 pictures
* via an `h262_context_p`, as it does not maintain the "last item read"
* information therein.
*
* - `es` is the elementary stream we're reading from.
* - `item` is the datastructure containing the MPEG2 item found, or NULL
* if there was none.
*
* Returns 0 if it succeeds, EOF if the end-of-file is read (i.e., there
* is no next MPEG2 item), otherwise 1 if some error occurs.
*/
extern int find_next_h262_item(ES_p es,
h262_item_p *item)
{
int err;
err = build_h262_item(item);
if (err) return 1;
err = find_next_ES_unit(es,&(*item)->unit);
if (err) // 1 or EOF
{
free_h262_item(item);
return err;
}
// If this is a picture, we can do a little more
if ((*item)->unit.start_code == 0)
{
(*item)->picture_coding_type = ((*item)->unit.data[5] & 0x38) >> 3;
}
return 0;
}
/*
* Build a new H.262 picture reading context.
*
* This acts as a "jacket" around the ES context, and is used when reading
* H.262 pictures with get_next_h262_picture(). It "remembers" the last
* item read, which is the first item that was not part of the picture.
*
* Returns 0 if it succeeds, 1 if some error occurs.
*/
extern int build_h262_context(ES_p es,
h262_context_p *context)
{
h262_context_p new = malloc(SIZEOF_H262_CONTEXT);
if (new == NULL)
{
fprintf(stderr,"### Unable to allocate H.262 context datastructure\n");
return 1;
}
new->es = es;
new->picture_index = 0;
new->last_item = NULL;
new->reverse_data = NULL;
new->count_since_seq_hdr = 0;
new->last_aspect_ratio_info = H262_UNSET_ASPECT_RATIO_INFO;
new->last_afd = UNSET_AFD_BYTE;
new->add_fake_afd = FALSE;
*context = new;
return 0;
}
/*
* Free an H.262 picture reading context.
*
* Clears the datastructure, frees it, and returns `context` as NULL.
*
* Does not free any `reverse_data` datastructure.
*
* Does nothing if `context` is already NULL.
*/
extern void free_h262_context(h262_context_p *context)
{
h262_context_p cc = *context;
if (cc == NULL)
return;
if (cc->last_item != NULL)
free_h262_item(&cc->last_item);
cc->reverse_data = NULL;
free(*context);
*context = NULL;
return;
}
/*
* Rewind a file being read as H.262 pictures
*
* This is a wrapper for `seek_ES` that also knows to unset things appropriate
* to the H.262 picture reading context.
*
* If a reverse context is attached to this context, it also will
* be "rewound" appropriately.
*
* Returns 0 if all goes well, 1 if something goes wrong.
*/
extern int rewind_h262_context(h262_context_p context)
{
ES_offset start_of_file = {0,0};
// First, forget where we are
if (context->last_item)
free_h262_item(&context->last_item);
context->picture_index = 0; // no pictures read from this file yet
// Next, take care of rewinding
if (context->reverse_data)
{
context->reverse_data->last_posn_added = -1; // next entry to be 0
context->count_since_seq_hdr = 0; // what else can we do?
}
// And then, do the relocation itself
return seek_ES(context->es,start_of_file);
}
// ------------------------------------------------------------
// MPEG2 "pictures"
// ------------------------------------------------------------
/*
* Add (the information from) an H.262 item to the given picture.
*
* Note that since this takes a copy of the ES unit data from within the item,
* it is safe to free the original item.
*
* Returns 0 if it succeeds, 1 if some error occurs.
*/
static int append_to_h262_picture(h262_picture_p picture,
h262_item_p item)
{
ES_unit_p unit = &(item->unit);
if (is_h262_extension_start_item(item))
{
byte *data = unit->data;
int extension_start_code_id = (data[4] & 0xF0) >> 4;
if (extension_start_code_id == 1) // sequence extension
{
picture->progressive_sequence = data[5] & 0x08;
}
else if (extension_start_code_id == 8) // picture coding extension
{
picture->picture_structure = data[6] & 0x03;
}
}
return append_to_ES_unit_list(picture->list,unit);
}
/*
* Build a new H.262 "picture", starting with the given item (which is
* copied, so may be freed after this call).
*
* Returns 0 if it succeeds, 1 if some error occurs.
*/
static int build_h262_picture(h262_context_p context,
h262_picture_p *picture,
h262_item_p item)
{
int err;
ES_unit_p unit = &(item->unit);
byte *data = unit->data;
h262_picture_p new = malloc(SIZEOF_H262_PICTURE);
if (new == NULL)
{
fprintf(stderr,"### Unable to allocate H.262 picture datastructure\n");
return 1;
}
err = build_ES_unit_list(&(new->list));
if (err)
{
fprintf(stderr,"### Unable to allocate internal list for H.262 picture\n");
free(new);
return 1;
}
// Deduce what we can from the first item of the "picture"
if (is_h262_picture_item(item))
{
new->picture_coding_type = item->picture_coding_type;
new->is_picture = TRUE;
new->is_sequence_header = FALSE;
new->temporal_reference = (data[4] << 2) | ((data[5] & 0xC0) >> 6);
// Assume that our picture is a frame, until we're told otherwise
// (MPEG-1 data will never tell us otherwise)
new->picture_structure = 3;
new->was_two_fields = FALSE;
// Assume the last AFD and aspect ratio info until told otherwise
new->afd = context->last_afd;
new->aspect_ratio_info = context->last_aspect_ratio_info;
new->is_real_afd = FALSE;
}
else if (is_h262_seq_header_item(item))
{
new->is_picture = FALSE;
new->is_sequence_header = TRUE;
new->picture_coding_type = 0; // Forbidden value, just in case
new->aspect_ratio_info = (data[7] & 0xF0) >> 4;
// Assume that we are only allowed progressive frames, until we're told
// otherwise (MPEG-1 data will never tell us otherwise)
new->progressive_sequence = 1;
}
else if (is_h262_seq_end_item(item))
{
new->is_picture = FALSE;
new->is_sequence_header = FALSE;
new->picture_coding_type = 0; // Forbidden value, just in case
}
else
{
fprintf(stderr,
"!!! Building H.262 picture that starts with a %s (%02x)\n",
H262_START_CODE_STR(item->unit.start_code),item->unit.start_code);
new->is_picture = FALSE;
new->is_sequence_header = FALSE;
new->picture_coding_type = 0; // Forbidden value, just in case
}
err = append_to_h262_picture(new,item);
if (err)
{
fprintf(stderr,"### Error appending first item to H.262 %s\n",
H262_START_CODE_STR(item->unit.start_code));
free_h262_picture(&new);
return 1;
}
*picture = new;
return 0;
}
/*
* Build a "pretend" H262 item containing an AFD user data field, and
* append it to the given picture.
*
* Returns 0 if it succeeds, 1 if some error occurs.
*/
static int append_fake_afd(h262_picture_p picture,
byte afd)
{
int err;
static h262_item_p item = NULL;
if (item == NULL)
{
err = build_h262_item(&item);
if (err)
{
fprintf(stderr,"### Error building 'fake' AFD for H.262 picture\n");
return 1;
}
item->unit.data[0] = 0x00;
item->unit.data[1] = 0x00;
item->unit.data[2] = 0x01;
item->unit.data[3] = 0xb2;
item->unit.data[4] = 0x44;
item->unit.data[5] = 0x54;
item->unit.data[6] = 0x47;
item->unit.data[7] = 0x31;
item->unit.data[8] = 0x41;
item->unit.data[9] = afd;
item->unit.data_len = 10;
item->unit.start_code = 0xb2;
}
else
item->unit.data[9] = afd;
// Remember, this *copies* the item, so we can use it again later on
err = append_to_h262_picture(picture,item);
if (err)
{
fprintf(stderr,"### Error appending 'fake' AFD to H.262 picture\n");
return 1;
}
picture->afd = afd;
picture->is_real_afd = FALSE;
return 0;
}
/*
* Merge two fields into one (frame) picture.
*
* - `picture1` is the first field.
* - `picture2` is the second field, which will be merged into the first
* (thus `picture2` may be freed after this function succeeds).
*
* Returns 0 if it succeeds, 1 if some error occurs.
*/
static int merge_fields(h262_picture_p picture1,
h262_picture_p picture2)
{
int ii;
for (ii = 0; ii < picture2->list->length; ii++)
{
int err = append_to_ES_unit_list(picture1->list,
&picture2->list->array[ii]);
if (err)
{
fprintf(stderr,"### Error merging two H.262 field pictures\n");
return 1;
}
}
picture1->was_two_fields = TRUE;
return 0;
}
/*
* Free an H.262 "picture".
*
* Clears the datastructure, frees it, and returns `picture` as NULL.
*
* Does nothing if `picture` is already NULL.
*/
extern void free_h262_picture(h262_picture_p *picture)
{
h262_picture_p pic = *picture;
if (pic == NULL)
return;
if (pic->list != NULL)
free_ES_unit_list(&pic->list);
free(*picture);
*picture = NULL;
return;
}
/*
* Compare two H.262 pictures. The comparison does not include the start
* position of the picture, but just the actual data - i.e., two pictures
* read from different locations in the input stream may be considered the
* same if their data content is identical.
*
* Returns TRUE if the lists contain identical content, FALSE otherwise.
*/
extern int same_h262_picture(h262_picture_p picture1,
h262_picture_p picture2)
{
if (picture1 == picture2)
return TRUE;
else if (picture1 == NULL || picture2 == NULL)
return FALSE;
else
return same_ES_unit_list(picture1->list,picture2->list);
}
/*
* Remember a picture for future reversing, if it's an I picture or a
* sequence header
*
* Returns 0 if it succeeds, 1 if some error occurs.
*/
static int maybe_remember_this_picture(h262_context_p h262,
int verbose,
h262_picture_p this_picture)
{
int err;
ES_offset start_posn = {0,0};
u_int32 num_bytes = 0;
if (this_picture->is_picture)
{
if (this_picture->picture_coding_type == 1)
{
// It's an I picture - we want to remember it in our reverse list
(h262->count_since_seq_hdr) ++;
err = get_ES_unit_list_bounds(this_picture->list,&start_posn,&num_bytes);
if (err)
{
fprintf(stderr,
"### Error working out position/size of H.262 picture\n");
return 1;
}
err = remember_reverse_h262_data(h262->reverse_data,h262->picture_index,
start_posn,num_bytes,
h262->count_since_seq_hdr,
this_picture->afd);
if (err)
{
fprintf(stderr,
"### Error remembering reversing data for H.262 item\n");
return 1;
}
if (verbose)
printf("REMEMBER I picture %5d at " OFFSET_T_FORMAT_08
"/%04d for %5d\n",h262->picture_index,
start_posn.infile,start_posn.inpacket,num_bytes);
}
}
else if (this_picture->is_sequence_header)
{
// It's a sequence header - remember it for the next picture
h262->count_since_seq_hdr = 0;
err = get_ES_unit_list_bounds(this_picture->list,&start_posn,&num_bytes);
if (err)
{
fprintf(stderr,"### Error working out position/size of H.262"
" sequence header for reversing data\n");
return 1;
}
err = remember_reverse_h262_data(h262->reverse_data,0,
start_posn,num_bytes,0,0);
if (err)
{
fprintf(stderr,"### Error remembering reversing data for H.262 item\n");
return 1;
}
if (verbose)
printf("REMEMBER Sequence header at " OFFSET_T_FORMAT_08
"/%04d for %5d\n",
start_posn.infile,start_posn.inpacket,num_bytes);
}
return 0;
}
/*
* Given an MPEG-2 user data item containing an AFD (as indicated by the
* ``is_h262_AFD_user_data_item`` macro), extract the actual AFD.
*
* NB: the whole byte containing the AFD is returned, including the top
* '1111' bits.
*
* Returns 0 if all goes well, 1 if the AFD user data item is malformed
* (in which case a message will have been written out to ``stderr``, but
* the "apparent" AFD value will still be returned).
*/
static int extract_AFD(h262_item_p item,
byte *afd)
{
if (item->unit.data[8] == 0x41)
{
// AFD flag set
if (item->unit.data_len < 10)
{
fprintf(stderr,"!!! AFD too short (only %d bytes - AFD missing)\n",
item->unit.data_len);
*afd = UNSET_AFD_BYTE;
return 1;
}
*afd = item->unit.data[9];
if ((item->unit.data[9] & 0xF0) != 0xF0)
{
fprintf(stderr,"### Bad AFD %02x (reserved bits not 1111)\n",
item->unit.data[9]);
return 1;
}
}
else if (item->unit.data[8] == 0x01)
{
*afd = UNSET_AFD_BYTE; // no explicit AFD - use the default
}
else
{
fprintf(stderr,"### AFD datastructure malformed: flag byte is %02x"
" instead of 0x41 or 0x01\n",item->unit.data[8]);
if (item->unit.data_len == 9)
*afd = UNSET_AFD_BYTE;
else
*afd = item->unit.data[9];
return 1;
}
return 0;
}
#if DEBUG_GET_NEXT_PICTURE
/*
* Print a representation of an item for debugging
*/
static void _show_item(h262_item_p item)
{
printf("__ ");
if (item == NULL)
{
printf("<no item>\n");
return;
}
if (is_h262_picture_item(item))
printf("%s picture",H262_PICTURE_CODING_STR(item->picture_coding_type));
else if (is_h262_slice_item(item))
printf("slice %2x",item->unit.start_code);
else
printf("%s",H262_START_CODE_STR(item->unit.start_code));
printf(" at " OFFSET_T_FORMAT "/%d for %d\n",
item->unit.start_posn.infile,item->unit.start_posn.inpacket,
item->unit.data_len);
}
#endif
/*
* Retrieve the the next H.262 "picture".
*
* The H.262 "picture" returned can be one of:
*
* 1. A field or frame, including its slices.
* 2. A sequence header, including its sequence extension, if any.
* 3. A sequence end.
*
* - `context` is the H.262 picture reading context.
* - if `verbose` is true, then extra information will be output
* - if `quiet` is true, then only errors will be reported
* - `picture` is the H.262 "picture", containing a field or frame picture,
* a sequence header or a sequence end
*
* Returns 0 if it succeeds, EOF if we reach the end of file, or 1 if some
* error occurs.
*/
extern int get_next_h262_single_picture(h262_context_p context,
int verbose,
h262_picture_p *picture)
{
int err = 0;
int in_sequence_header = FALSE;
int in_sequence_end = FALSE;
int in_picture = FALSE;
int last_was_slice = FALSE;
int had_afd = FALSE;
h262_item_p item = context->last_item;
#if DEBUG_GET_NEXT_PICTURE
int num_slices = 0;
int had_slice = FALSE;
int last_slice_start_code = 0;
if (verbose && context->last_item) printf("__ reuse last item\n");
#endif
context->last_item = NULL;
// Find the first item of our next "picture"
for (;;)
{
if (item == NULL)
{
err = find_next_h262_item(context->es,&item);
if (err) return err;
}
if (is_h262_picture_item(item))
{
in_picture = TRUE;
break;
}
else if (is_h262_seq_header_item(item))
{
in_sequence_header = TRUE;
break;
}
else if (is_h262_seq_end_item(item))
{
in_sequence_end = TRUE;
break;
}
#if DEBUG_GET_NEXT_PICTURE
else if (verbose)
_show_item(item);
#endif
free_h262_item(&item);
}
#if DEBUG_GET_NEXT_PICTURE
if (verbose)
{
printf("__ --------------------------------- <start picture>\n");
_show_item(item);
}
#endif
err = build_h262_picture(context,picture,item);
if (err) return 1;
free_h262_item(&item);
if (in_sequence_end)
{
// A sequence end is a single item, so we're done
#if DEBUG_GET_NEXT_PICTURE
if (verbose)
printf("__ --------------------------------- <end picture>\n");
#endif
return 0;
}
// Now find all the rest of the picture/sequence header
for (;;)
{
err = find_next_h262_item(context->es,&item);
if (err)
{
if (err != EOF)
free_h262_picture(picture);
return err;
}
if (in_picture)
{
// Have we just finished a picture?
// We know we have if the last item was a slice, but this one isn't
if (last_was_slice && !is_h262_slice_item(item))
break;
last_was_slice = is_h262_slice_item(item);
}
else if (in_sequence_header)
{
// Have we just finished a sequence header and its friends?
// We know we have if we've hit something that isn't an
// extension start or user data start code (perhaps we could
// get away with just keeping the (in MPEG-2) sequence_extension,
// but it's safer (and simpler) to keep the lot
if (!is_h262_extension_start_item(item) &&
!is_h262_user_data_item(item))
break;
}
if (in_picture)
{
if (is_h262_AFD_user_data_item(item))
{
// We found a *real* AFD - remember it
err = extract_AFD(item,&(*picture)->afd);
if (err)
fprintf(stderr,"!!! Assuming AFD %x at " OFFSET_T_FORMAT "/%d\n",
(*picture)->afd,
item->unit.start_posn.infile,item->unit.start_posn.inpacket);
(*picture)->is_real_afd = TRUE;
#if DEBUG_AFD
if ((*picture)->afd != context->last_afd)
{
printf("* ");
report_h262_picture(stdout,*picture,FALSE);
}
#endif
context->last_afd = (*picture)->afd;
had_afd = TRUE;
}
else if (context->add_fake_afd && !had_afd && is_h262_slice_item(item))
{
// We've been asked to fake AFDs for pictures that don't have them,
// and this is the first slice of a picture, so now (i.e., before
// said first slice) is the time to add in that faked AFD
err = append_fake_afd(*picture,context->last_afd);
if (err)
{
free_h262_picture(picture);
return 1;
}
had_afd = TRUE; // well, sort of
#if DEBUG_GET_NEXT_PICTURE
if (verbose)
{
printf("__ fake AFD ");
print_bits(stdout,4,(*picture)->afd);
printf(", i.e., %s",SHORT_AFD_STR((*picture)->afd));
printf("\n");
}
#endif
}
}
#if DEBUG_GET_NEXT_PICTURE
if (verbose)
{
if (!had_slice)
_show_item(item);
if (is_h262_slice_item(item))
{
num_slices ++;
last_slice_start_code = item->unit.start_code;
if (!had_slice)
had_slice = TRUE;
}
}
#endif
// Don't forget to remember the actual item
err = append_to_h262_picture(*picture,item);
if (err)
{
fprintf(stderr,"### Error adding item to H.262 sequence header\n");
free_h262_picture(picture);
return 1;
}
free_h262_item(&item);
}
if (in_picture)
context->picture_index ++;
else
context->last_aspect_ratio_info = (*picture)->aspect_ratio_info;
context->last_item = item;
#if DEBUG_GET_NEXT_PICTURE
if (verbose)
{
if (in_picture)
{
if (num_slices > 1)
{
ES_unit_p unit = &(*picture)->list->array[(*picture)->list->length-1];
printf("__ ...\n");
printf("__ slice %2x",last_slice_start_code);
printf(" at " OFFSET_T_FORMAT "/%d for %d\n",
unit->start_posn.infile,unit->start_posn.inpacket,
unit->data_len);
}
printf("__ (%2d slices)\n",num_slices);
}
printf("__ --------------------------------- <end picture>\n");
if (in_picture || in_sequence_header)
_show_item(item);
}
#endif
return 0;
}
/*
* Try for the next field of a pair, and return a frame formed thereof
*
* - `context` is the H.262 picture reading context.
* - if `verbose` is true, then extra information will be output
* - if `quiet` is true, then only errors will be reported
* - if `first_time` is true, then we will try to match a second field
* with a third, if the second field has a different temporal reference
* than the first. If it is false, we will not (thus stopping us from
* trying forever...)
* - `picture` starts out at the first field of our (hoped for) pair, and
* will end up as the merged result of our two fields. If the input stream
* is awry (or we are misaligned with respect to it), this might instead be
* replaced by a "proper" frame, or even a sequence header.
*
* Returns 0 if it succeeds, EOF if we reach the end of file or have
* read the sequence_end_code, or 1 if some error occurs.
*/
static int get_next_field_of_pair(h262_context_p context,
int verbose,
int quiet,
int first_time,
h262_picture_p *picture)
{
int err;
h262_picture_p second;
if (verbose)
printf("@@ Looking for second field (%s time)\n",
(first_time?"first":"second"));
// We assume (hope) the next picture will be our second half
err = get_next_h262_single_picture(context,verbose,&second);
if (err)
{
if (err != EOF)
fprintf(stderr,"### Trying to read second field\n");
return err;
}
if (!is_h262_field_picture(second))
{
// But it was either a frame or a sequence header - oh dear
if (!quiet)
fprintf(stderr,"!!! Field followed by a %s - ignoring the field\n",
(second->is_picture?"frame":"sequence header"));
free_h262_picture(picture);
*picture = second;
// and pretend to success
}
else if ((*picture)->temporal_reference == second->temporal_reference)
{
// They appear to be matching fields - make a frame from them
if (verbose) printf("@@ Merging two fields\n");
err = merge_fields(*picture,second);
if (err)
{
free_h262_picture(&second);
return 1;
}
free_h262_picture(&second);
}
else if (first_time)
{
if (!quiet)
fprintf(stderr,"!!! Field with temporal ref %d (%x) followed by"
" field with temporal ref %d (%x) - ignoring first field\n",
(*picture)->temporal_reference,(*picture)->temporal_reference,
second->temporal_reference,second->temporal_reference);
// Try again
free_h262_picture(picture);
*picture = second;
err = get_next_field_of_pair(context,verbose,quiet,FALSE,picture);
if (err) return 1;
}
else
{
fprintf(stderr,"### Adjacent fields do not share temporal references"
" - unable to match fields up\n");
return 1;
}
return 0;
}
/*
* Retrieve the the next H.262 "picture".
*
* The H.262 "picture" returned can be one of:
*
* 1. A frame, including its slices. This may be the concatenation of two
* adjacent field pictures.
* 2. A sequence header, including its sequence extension, if any.
* 3. A sequence end.
*
* Specifically, the next H.262 "picture" is retrieved from the input stream.
*
* If that "picture" represents a sequence header or a frame, it is returned.
*
* If it represents a field, then the *following* "picture" is retrieved, and
* if that is the second field of its frame, it is merged into the first,
* and the resultant frame is returned.
*
* If a field with temporal reference A is followed by a field with temporal
* reference B, it is assumed that synchronisation has been lost. In this
* case, the first field (frame A) will be discarded, and an attempt made to
* read the second field of frame B.
*
* Similarly, if a frame or sequence header is found instead of the second
* field, the first field will be discarded and the frame returned.
*
* Note that if the context is associated with a reverse context,
* then appropriate frames/sequence headers will automatically be
* remembered therein.
*
* Also note that it is assumed that the AFD for adjacent fields will be
* the same.
*
* - `context` is the H.262 picture reading context.
* - if `verbose` is true, then extra information will be output
* - if `quiet` is true, then only errors will be reported
* - `picture` is the H.262 "picture", containing a frame picture,
* a sequence header or a sequence end
*
* Returns 0 if it succeeds, EOF if we reach the end of file, or 1 if some
* error occurs.
*/
extern int get_next_h262_frame(h262_context_p context,
int verbose,
int quiet,
h262_picture_p *picture)
{
int err;
err = get_next_h262_single_picture(context,verbose,picture);
if (err) return err;
if (is_h262_field_picture(*picture))
{
// We assume (hope) the next picture will be our second half
// - let's try to get it, and merge it into our current picture
err = get_next_field_of_pair(context,verbose,quiet,TRUE,picture);
if (err)
{
free_h262_picture(picture);
return 1;
}
}
if (context->reverse_data)
{
err = maybe_remember_this_picture(context,verbose,*picture);
if (err)
{
free_h262_picture(picture);
return 1;
}
}
return 0;
}
/*
* Write out an H.262 picture as TS
*
* - `tswriter` is TS the output stream
* - `picture` is the picture to write out
* - `pid` is the PID to use for the TS packets
*
* Returns 0 if it succeeds, 1 if some error occurs.
*/
extern int write_h262_picture_as_TS(TS_writer_p tswriter,
h262_picture_p picture,
u_int32 pid)
{
int ii;
ES_unit_list_p list;
if (picture == NULL || picture->list == NULL)
return 0;
list = picture->list;
for (ii = 0; ii < list->length; ii++)
{
int err;
ES_unit_p unit = &(list->array[ii]);
err = write_ES_as_TS_PES_packet(tswriter,unit->data,unit->data_len,pid,
DEFAULT_VIDEO_STREAM_ID);
if (err)
{
fprintf(stderr,"### Error writing out picture list to TS\n");
return err;
}
}
return 0;
}
/*
* Write out a picture (as stored in an ES unit list) as ES
*
* - `output` is the ES output file
* - `picture` is the picture to write out
*
* Returns 0 if it succeeds, 1 if some error occurs.
*/
extern int write_h262_picture_as_ES(FILE *output,
h262_picture_p picture)
{
int ii;
ES_unit_list_p list;
if (picture == NULL || picture->list == NULL)
return 0;
list = picture->list;
for (ii = 0; ii < list->length; ii++)
{
int err;
ES_unit_p unit = &(list->array[ii]);
err = write_ES_unit(output,unit);
if (err)
{
fprintf(stderr,"### Error writing out picture list to ES\n");
return err;
}
}
return 0;
}
/*
* Report on an H.262 picture's contents.
*
* - `stream` is where to write the information
* - `picture` is the picture to report on
* - if `report_data`, then the component ES units will be printed out as well
*/
extern void report_h262_picture(FILE *stream,
h262_picture_p picture,
int report_data)
{
if (picture->is_picture)
{
printf("%s %s #%02d",
H262_PICTURE_CODING_STR(picture->picture_coding_type),
H262_PICTURE_STRUCTURE_STR(picture->picture_structure),
picture->temporal_reference);
if (picture->was_two_fields)
printf(" (merged)");
printf(" %s",H262_ASPECT_RATIO_INFO_STR(picture->aspect_ratio_info));
if (picture->is_real_afd)
printf(" AFD ");
else
printf(" afd ");
print_bits(stdout,4,picture->afd);
printf(", i.e., %s",SHORT_AFD_STR(picture->afd));
printf("\n");
}
else if (picture->is_sequence_header)
{
printf("Sequence header: ");
switch (picture->progressive_sequence)
{
case 0: printf("frames and fields"); break;
case 1: printf("progressive frames only"); break;
default:
printf("progressive_sequence=%d",
picture->progressive_sequence);
break;
}
printf(", aspect ratio %s",
H262_ASPECT_RATIO_INFO_STR(picture->aspect_ratio_info));
printf("\n");
}
else
{
printf("Sequence end\n");
}
if (report_data)
report_ES_unit_list(stream,"ES units",picture->list);
}
// Local Variables:
// tab-width: 8
// indent-tabs-mode: nil
// c-basic-offset: 2
// End:
// vim: set tabstop=8 shiftwidth=2 expandtab:
Reference in New Issue View Git Blame Kopiuj bezpośredni odnośnik