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reverse.c
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/*
* Support for reversing
*
* ***** 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 *****
*/
/* The reverse-data arrays are populated as a side-effect of processing the
* file forwards. The "build a picture" routines in h262.c and accessunit.c
* call the "remember" functions herein for appropriate pictures.
*
* Reversing is then handled by going backwards through those arrays, selecting
* appropriate "rememebered" values. For H.264 pictures, and for H.262 sequence
* headers, it is sufficient to read the appropriate "chunk" of memory back
* in (from the ES data stream), and just output that without any further work.
*
* For H.262 pictures, life is a little more complex, as some of the frames
* contain AFD user data, which overrides the aspect ratio in the preceding
* sequence header. If one thus wants to precede each frame *with* a sequence
* header (which is a Good Idea), then one also needs to ensure it has an
* appropriate AFD entry (whether it did in the original data or not).
*
* Thus for H.262 pictures, one must re-read the picture data from the input
* file (starting at the specified offset), and "invent" an AFD entry within
* its item list, if necessary.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <time.h> // for ctime/time
#include "compat.h"
#include "misc_defns.h"
#include "printing_fns.h"
#include "es_fns.h"
#include "h262_fns.h"
#include "nalunit_fns.h"
#include "accessunit_fns.h"
#include "ts_fns.h"
#include "tswrite_fns.h"
#include "reverse_fns.h"
#define DEBUG 0
// ------------------------------------------------------------
// A useful macro to tell us if the `idx` entry in the reverse_data
// structure `rev` is a sequence header or not (or did you guess?)
#define SEQUENCE_HEADER_ENTRY(rev,idx) (!(rev)->is_h264 && \
(rev)->seq_offset[idx] == 0)
// ============================================================
// Remembering start/length information for reversing video sequences
// ============================================================
/*
* Build the internal arrays to remember video sequence bounds in,
* for reversing.
*
* Builds a new `reverse_data` datastructure. If `is_h264` is FALSE (i.e., the
* data to be reversed is not MPEG-1 or MPEG-2), then this datastructure may
* be smaller.
*
* To collect reversing data, attach this datastructure to an H.262 or access
* unit context (with add_h262/access_unit_reverse_context), and then use
* get_next_h262_frame() or get_next_h264_frame() to read through the data
* stream - appropriate pictures/access units will be remembered
* automatically.
*
* Returns 0 if it succeeds, 1 if some error occurs.
*/
extern int build_reverse_data(reverse_data_p *reverse_data,
int is_h264)
{
int newsize = REVERSE_ARRAY_START_SIZE;
reverse_data_p new = malloc(SIZEOF_REVERSE_DATA);
if (new == NULL)
{
print_err("### Unable to allocate reverse data datastructure\n");
return 1;
}
new->start_file = malloc(newsize*sizeof(offset_t));
if (new->start_file == NULL)
{
print_err("### Unable to allocate reverse data array (start_file)\n");
free(new);
return 1;
}
new->start_pkt = malloc(newsize*sizeof(int32_t));
if (new->start_pkt == NULL)
{
print_err("### Unable to allocate reverse data array (start_pkt)\n");
free(new->start_file);
free(new);
return 1;
}
new->index = malloc(newsize*sizeof(uint32_t));
if (new->index == NULL)
{
print_err("### Unable to allocate reverse data array (index)\n");
free(new->start_file);
free(new->start_pkt);
free(new);
return 1;
}
new->data_len = malloc(newsize*sizeof(int32_t));
if (new->data_len == NULL)
{
print_err("### Unable to allocate reverse data array (data_len)\n");
free(new->start_file);
free(new->start_pkt);
free(new->index);
free(new);
return 1;
}
if (is_h264)
{
new->seq_offset = NULL;
new->afd_byte = NULL;
}
else
{
new->seq_offset = malloc(newsize);
if (new->seq_offset == NULL)
{
print_err("### Unable to allocate reverse data array (seq offset)\n");
free(new->start_file);
free(new->start_pkt);
free(new->index);
free(new->data_len);
free(new);
return 1;
}
new->afd_byte = malloc(newsize);
if (new->afd_byte == NULL)
{
print_err("### Unable to allocate reverse data array (AFD)\n");
free(new->seq_offset);
free(new->start_file);
free(new->start_pkt);
free(new->index);
free(new->data_len);
free(new);
return 1;
}
}
new->size = newsize;
new->length = 0;
new->num_pictures = 0;
new->is_h264 = is_h264;
new->pictures_written = 0;
new->pictures_kept = 0;
new->first_written = 0;
new->last_written = 0;
new->last_posn_added = 0; // although undefined if `length` == 0
new->output_sequence_headers = !is_h264;
new->pid = DEFAULT_VIDEO_PID;
new->stream_id = DEFAULT_VIDEO_STREAM_ID;
*reverse_data = new;
return 0;
}
/*
* Set the video PID and stream id for TS output.
*
* This need only be called if reverse data *is* being output as TS,
* and if the standard default values (DEFAULT_VIDEO_PID and
* DEFAULT_VIDEO_STREAM_ID) are not correct.
*/
extern void set_reverse_pid(reverse_data_p reverse_data,
uint32_t pid,
byte stream_id)
{
reverse_data->pid = pid;
reverse_data->stream_id = stream_id;
}
/*
* Add a reversing context to an H.262 context (and vice versa).
*
* Does not check if there is one present already.
*
* Returns 0 if all is well, 1 if something goes wrong.
*/
extern int add_h262_reverse_context(h262_context_p h262,
reverse_data_p reverse_data)
{
if (reverse_data->is_h264)
{
print_err("### Cannot add an H.262 context to an H.264 reverse data"
" context\n");
return 1;
}
h262->reverse_data = reverse_data;
reverse_data->h262 = h262;
return 0;
}
/*
* Add a reversing context to an access unit context (and vice versa).
*
* Does not check if there is one present already.
*
* Returns 0 if all is well, 1 if something goes wrong.
*/
extern int add_access_unit_reverse_context(access_unit_context_p context,
reverse_data_p reverse_data)
{
if (!reverse_data->is_h264)
{
print_err("### Cannot add an H.264 access unit context to an"
" H.262 reverse data context\n");
return 1;
}
context->reverse_data = reverse_data;
reverse_data->h264 = context;
return 0;
}
/*
* Free the datastructure we used to remember reversing data
*
* Sets `reverse_data` to NULL.
*/
extern void free_reverse_data(reverse_data_p *reverse_data)
{
reverse_data_p this = *reverse_data;
if (this == NULL)
return;
if (this->seq_offset != NULL)
{
free(this->seq_offset);
this->seq_offset = NULL;
}
free(this->index);
free(this->start_file);
free(this->start_pkt);
free(this->data_len);
this->index = NULL;
this->start_file = NULL;
this->start_pkt = NULL;
this->data_len = NULL;
this->length = this->size = 0;
free(this);
*reverse_data = NULL;
}
/*
* Compare an offset and two position components. `offset2` is composed
* of file_posn2 and pkt_posn2.
*
* Returns -1 if offset1 < offset2, 0 if they are the same, and 1 if
* offset1 > offset2.
*/
static inline int cmp_offsets(ES_offset offset1,
offset_t file_posn2,
int32_t pkt_posn2)
{
if (offset1.infile < file_posn2)
return -1;
else if (offset1.infile > file_posn2)
return 1;
else if (offset1.inpacket < pkt_posn2)
return -1;
else if (offset1.inpacket > pkt_posn2)
return 1;
else
return 0;
}
static void debug_reverse_data_problem(reverse_data_p reverse_data,
uint32_t index,
ES_offset start_posn,
uint32_t idx)
{
FILE *tempfile;
char *tempfilename = "tsserve_reverse_problem.txt";
int ii;
tempfile = fopen(tempfilename,"a+");
if (tempfile == NULL)
{
fprint_err("### Unable to open file %s - writing diagnostics"
" to stderr instead\n",tempfilename);
tempfile = stderr;
}
else
{
time_t now;
fprint_err("### Appending diagnostics to file %s\n",tempfilename);
now = time(NULL);
fprintf(tempfile,"** %s:\n",ctime(&now));
}
fprintf(tempfile,"Trying to add reverse data [%d] " OFFSET_T_FORMAT
"/%d at index %d (again),\nbut previous entry was [%d] "
OFFSET_T_FORMAT "/%d\n",
index,start_posn.infile,start_posn.inpacket,idx,
reverse_data->index[idx],reverse_data->start_file[idx],
reverse_data->start_pkt[idx]);
fprintf(tempfile,"Last posn added %d, length %d, index %d\n",
reverse_data->last_posn_added,reverse_data->length,index);
for (ii=0; ii<reverse_data->length; ii++)
if (reverse_data->is_h264 || reverse_data->seq_offset[ii])
fprintf(tempfile," %3d: %4d at " OFFSET_T_FORMAT "/%d for %d\n",
ii,reverse_data->index[ii],
reverse_data->start_file[ii],
reverse_data->start_pkt[ii],
reverse_data->data_len[ii]);
else
fprintf(tempfile," %3d: seqh at " OFFSET_T_FORMAT "/%d for %d\n",
ii,
reverse_data->start_file[ii],
reverse_data->start_pkt[ii],
reverse_data->data_len[ii]);
if (tempfile != stderr)
{
fprintf(tempfile,"\n \n");
fclose(tempfile);
}
}
/*
* Remember video sequence bounds for H.262 data
*
* - `reverse_data` is the datastructure we want to add our entry to
* - `index` indicates which picture (counted from the start of the file)
* this one is (i.e., we're assuming that not all pictures will be stored).
* If the entry is an H.262 sequence header, then this is ignored.
* - `start_posn` is the location of the start of the entry in the file,
* The entry will be ignored if `start_posn` comes before the last
* existing entry in the arrays.
* - `length` is the number of bytes in the entry
* - `seq_offset` should be 0 for a sequence header, and is otherwise the
* offset backwards to the previous nearest sequence header (i.e., 1 if
* the sequence header is the previous entry).
* - `afd` is the effective AFD byte for this picture
*
* Returns 0 if it succeeds, 1 if some error occurs.
*/
extern int remember_reverse_h262_data(reverse_data_p reverse_data,
uint32_t index,
ES_offset start_posn,
uint32_t length,
byte seq_offset,
byte afd)
{
if (reverse_data->length > 0 &&
(reverse_data->last_posn_added + 1) < (uint32_t)reverse_data->length)
{
// We're repeating an entry we previously added - check it hasn't
// changed (since the only obvious way for this to have happened
// is if we've rewound and are then moving forwards again, it should
// not be possible for the data to have changed at a particular index)
int idx = reverse_data->last_posn_added + 1;
int cmp = cmp_offsets(start_posn,
reverse_data->start_file[idx],
reverse_data->start_pkt[idx]);
if (cmp == 0)
{
#if DEBUG
fprint_msg("++ Added [%d] " OFFSET_T_FORMAT "/%d again\n",
index,start_posn.infile,start_posn.inpacket);
#endif
reverse_data->last_posn_added ++;
return 0;
}
else
{
fprint_err("### Trying to add reverse data [%d] " OFFSET_T_FORMAT
"/%d at index %d (again),\n but previous entry was [%d] "
OFFSET_T_FORMAT "/%d\n",
index,start_posn.infile,start_posn.inpacket,idx,
reverse_data->index[idx],reverse_data->start_file[idx],
reverse_data->start_pkt[idx]);
debug_reverse_data_problem(reverse_data,index,start_posn,idx);
return 1;
}
}
if (reverse_data->size == reverse_data->length)
{
int newsize = reverse_data->size + REVERSE_ARRAY_INCREMENT_SIZE;
reverse_data->index = realloc(reverse_data->index,
newsize*sizeof(uint32_t));
if (reverse_data->index == NULL)
{
print_err("### Unable to extend reverse data array (index)\n");
return 1;
}
reverse_data->start_file = realloc(reverse_data->start_file,
newsize*sizeof(offset_t));
if (reverse_data->start_file == NULL)
{
print_err("### Unable to extend reverse data array (start_file)\n");
return 1;
}
reverse_data->start_pkt = realloc(reverse_data->start_pkt,
newsize*sizeof(int32_t));
if (reverse_data->start_pkt == NULL)
{
print_err("### Unable to extend reverse data array (start_pkt)\n");
return 1;
}
reverse_data->data_len = realloc(reverse_data->data_len,
newsize*sizeof(int32_t));
if (reverse_data->data_len == NULL)
{
print_err("### Unable to extend reverse data array (length)\n");
return 1;
}
if (!reverse_data->is_h264)
{
reverse_data->seq_offset = realloc(reverse_data->seq_offset,newsize);
if (reverse_data->seq_offset == NULL)
{
print_err("### Unable to extend reverse data array (seq offset)\n");
return 1;
}
reverse_data->afd_byte = realloc(reverse_data->afd_byte,newsize);
if (reverse_data->afd_byte == NULL)
{
print_err("### Unable to extend reverse data array (AFD)\n");
return 1;
}
}
reverse_data->size = newsize;
}
// If we're not an H.262 sequence header, remember our index
if (seq_offset != 0)
{
reverse_data->num_pictures ++;
reverse_data->index[reverse_data->length] = index;
reverse_data->seq_offset[reverse_data->length] = seq_offset;
reverse_data->afd_byte[reverse_data->length] = afd;
}
else
{
reverse_data->index[reverse_data->length] = 0;
reverse_data->seq_offset[reverse_data->length] = 0;
reverse_data->afd_byte[reverse_data->length] = 0;
}
reverse_data->start_file[reverse_data->length] = start_posn.infile;
reverse_data->start_pkt[reverse_data->length] = start_posn.inpacket;
reverse_data->data_len[reverse_data->length] = length;
reverse_data->last_posn_added = reverse_data->length;
reverse_data->length ++;
return 0;
}
/*
* Remember video sequence bounds for H.264 data
*
* - `reverse_data` is the datastructure we want to add our entry to
* - `index` indicates which picture (counted from the start of the file)
* this one is (i.e., we're assuming that not all pictures will be stored).
* If the entry is an H.262 sequence header, then this is ignored.
* - `start_posn` is the location of the start of the entry in the file,
* The entry will be ignored if `start_posn` comes before the last
* existing entry in the arrays.
* - `length` is the number of bytes in the entry
*
* Returns 0 if it succeeds, 1 if some error occurs.
*/
extern int remember_reverse_h264_data(reverse_data_p reverse_data,
uint32_t index,
ES_offset start_posn,
uint32_t length)
{
if (reverse_data->length > 0 &&
(reverse_data->last_posn_added + 1) < (uint32_t)reverse_data->length)
{
// We're repeating an entry we previously added - check it hasn't
// changed (since the only obvious way for this to have happened
// is if we've rewound and are then moving forwards again, it should
// not be possible for the data to have changed at a particular index)
int idx = reverse_data->last_posn_added + 1;
int cmp = cmp_offsets(start_posn,
reverse_data->start_file[idx],
reverse_data->start_pkt[idx]);
if (cmp == 0)
{
#if DEBUG
fprint_msg("++ Added [%d] " OFFSET_T_FORMAT "/%d again\n",
index,start_posn.infile,start_posn.inpacket);
#endif
reverse_data->last_posn_added ++;
return 0;
}
else
{
fprint_err("### Trying to add reverse data [%d] " OFFSET_T_FORMAT
"/%d at index %d (again),\n but previous entry was [%d] "
OFFSET_T_FORMAT "/%d\n",
index,start_posn.infile,start_posn.inpacket,idx,
reverse_data->index[idx],reverse_data->start_file[idx],
reverse_data->start_pkt[idx]);
debug_reverse_data_problem(reverse_data,index,start_posn,idx);
return 1;
}
}
if (reverse_data->size == reverse_data->length)
{
int newsize = reverse_data->size + REVERSE_ARRAY_INCREMENT_SIZE;
reverse_data->index = realloc(reverse_data->index,
newsize*sizeof(uint32_t));
if (reverse_data->index == NULL)
{
print_err("### Unable to extend reverse data array (index)\n");
return 1;
}
reverse_data->start_file = realloc(reverse_data->start_file,
newsize*sizeof(offset_t));
if (reverse_data->start_file == NULL)
{
print_err("### Unable to extend reverse data array (start_file)\n");
return 1;
}
reverse_data->start_pkt = realloc(reverse_data->start_pkt,
newsize*sizeof(int32_t));
if (reverse_data->start_pkt == NULL)
{
print_err("### Unable to extend reverse data array (start_pkt)\n");
return 1;
}
reverse_data->data_len = realloc(reverse_data->data_len,
newsize*sizeof(int32_t));
if (reverse_data->data_len == NULL)
{
print_err("### Unable to extend reverse data array (length)\n");
return 1;
}
reverse_data->size = newsize;
}
reverse_data->num_pictures ++;
reverse_data->index[reverse_data->length] = index;
reverse_data->start_file[reverse_data->length] = start_posn.infile;
reverse_data->start_pkt[reverse_data->length] = start_posn.inpacket;
reverse_data->data_len[reverse_data->length] = length;
reverse_data->last_posn_added = reverse_data->length;
reverse_data->length ++;
return 0;
}
/*
* Retrieve video sequence bounds for entry `which`
*
* - `reverse_data` is the datastructure we want to get our entry from
* - `which` indicates which entry we'd like to retrieve. The first
* entry in the `reverse_data` is number 0.
* - `index` indicates which picture (counted from the start of the file)
* this one is (i.e., we're assuming that not all pictures will be stored).
* `index` may be passed as NULL if the value is of no interest - i.e.,
* typically when the entry is for an H.262 sequence header.
* The first picture in the file has index 1.
* - `start_posn` is the location of the start of the entry in the file,
* - `length` is the number of bytes in the entry
* - for H.262 data, if the entry is a picture, then `seq_offset` will
* be the offset backwards to the previous nearest sequence header
* (i.e., 1 if the sequence header is the previous entry), and if it is
* a sequence header, `seq_offset` will be 0. For H.264 data, the value
* will always be 0. `seq_offset` may be passed as NULL if the value is
* of no interest.
* - for H.262 data, if the entry is a picture, then `afd` will be its
* (effective) AFD byte. Otherwise it will be 0. `afd` may be passed as NULL
* if the value if of no interest.
*
* To clarify, all of the following are legitimate calls::
*
* err = get_reverse_data(reverse_data,10,&index,&start,&length,&offset,&afd);
* err = get_reverse_data(reverse_data,10,&index,&start,&length,NULL,NULL);
* err = get_reverse_data(reverse_data,10,NULL,&start,&length,NULL,NULL);
*
* Returns 0 if it succeeds, 1 if some error occurs.
*/
extern int get_reverse_data(reverse_data_p reverse_data,
int which,
uint32_t *index,
ES_offset *start_posn,
uint32_t *length,
byte *seq_offset,
byte *afd)
{
if (which >= reverse_data->length || which < 0)
{
fprint_err("Requested reverse data index (%d) is out of range 0-%d\n",
which,reverse_data->length-1);
return 1;
}
if (index != NULL)
*index = reverse_data->index[which];
start_posn->infile = reverse_data->start_file[which];
start_posn->inpacket = reverse_data->start_pkt[which];
*length = reverse_data->data_len[which];
if (seq_offset != NULL)
{
if (reverse_data->is_h264)
*seq_offset = 0;
else
*seq_offset = reverse_data->seq_offset[which];
}
if (afd != NULL)
{
if (reverse_data->is_h264)
*afd = 0;
else
*afd = reverse_data->afd_byte[which];
}
return 0;
}
// ============================================================
// Collecting pictures
// ============================================================
/*
* Locate and remember sequence headers and I pictures, for later reversal.
*
* - `h262` is the H.262 stream reading context
* - if `max` is non-zero, then collecting will stop after `max` pictures
* - if `verbose` is true, then extra information will be output
* - if `quiet` is true, then only errors will be reported
*
* Returns 0 if all went well, EOF if the end of file is reached,
* and 1 if an error occurred.
*
* If command input is enabled, then it can also return COMMAND_RETURN_CODE
* if the current command has changed.
*/
extern int collect_reverse_h262(h262_context_p h262,
int max,
int verbose,
int quiet)
{
int err = 0;
// In order to stop after `max` items, we need to count pictures
int picture_count = 0;
if (h262->reverse_data == NULL)
{
print_err("### Unable to collect reverse data for H.262 pictures\n");
print_err(" H.262 context does not have reverse data"
" information attached to it\n");
return 1;
}
for (;;)
{
h262_picture_p picture = NULL;
if (es_command_changed(h262->es))
return COMMAND_RETURN_CODE;
err = get_next_h262_frame(h262,verbose,quiet,&picture);
if (err == EOF)
return EOF;
else if (err)
return 1;
if (picture->is_picture)
picture_count ++;
free_h262_picture(&picture);
if (max > 0 && picture_count >= max)
break;
}
return 0;
}
/*
* Find IDR and I slices, and remember their access units for later output
* in reverse order.
*
* - `acontext` is the access unit reading context
* - if `max` is non-zero, then collecting will stop after `max` access units
* - if `verbose` is true, then extra information will be output
* - if `quiet` is true, then only errors will be reported
*
* Returns 0 if all went well, EOF if the end of file is reached,
* and 1 if an error occurred.
*
* If command input is enabled, then it can also return COMMAND_RETURN_CODE
* if the current command has changed.
*/
extern int collect_reverse_access_units(access_unit_context_p acontext,
int max,
int verbose,
int quiet)
{
int err = 0;
int access_unit_count = 0;
if (acontext->reverse_data == NULL)
{
print_err("### Unable to collect reverse data for access units\n");
print_err(" Access unit context does not have reverse data"
" information attached to it\n");
return 1;
}
for (;;)
{
access_unit_p access_unit;
if (es_command_changed(acontext->nac->es))
return COMMAND_RETURN_CODE;
if (verbose)
print_msg("\n");
err = get_next_h264_frame(acontext,quiet,verbose,&access_unit);
if (err == EOF)
return EOF;
else if (err)
return 1;
access_unit_count ++;
free_access_unit(&access_unit);
if (!verbose && !quiet && (access_unit_count % 5000 == 0))
fprint_msg("Scanned %d NAL units in %d frames,"
" remembered %d frames\n",
acontext->nac->count,access_unit_count,
acontext->reverse_data->length);
// Did the logical stream end after the last access unit?
if (acontext->end_of_stream)
{
if (!quiet) print_msg("Found End-of-stream NAL unit\n");
break;
}
if (max > 0 && access_unit_count >= max)
{
if (verbose)
fprint_msg("\nStopping because %d frames have been read\n",
access_unit_count);
break;
}
}
return 0;
}
/*
* Write out packet data as ES or TS
*
* ``extern`` (but unadvertised in a header file) so that it can be used
* internally in esreverse.c
*
* Note that the last two arguments (`pid` and `stream_id`) are only
* used if the data `is_TS`.
*/
extern int write_packet_data(WRITER output,
int as_TS,
byte data[],
int data_len,
uint32_t pid,
byte stream_id)
{
int err;
if (as_TS)
{
// If we're writing TS data, then wrap the whole thing up as PES and
// write it out as TS packets.
// Unfortunately, it's not *quite* that simple, as a PES packet has
// a length specified either as a 16 bit quantity, or as 0 (allowed
// for video data). And it is known that some pictures are longer
// than 65535 bytes.
err = write_ES_as_TS_PES_packet(output.ts_output,data,data_len,
pid,stream_id);
if (err)
{
print_err("### Error writing data as TS PES packet\n");
return 1;
}
}
else
{
// Otherwise, just write it out as is
size_t written = fwrite(data,1,data_len,output.es_output);
if (written != data_len)
{
fprint_err("### Error writing out data: %s\n"
" Wrote %d bytes instead of %d\n",
strerror(errno),(int)written,data_len);
return 1;
}
}
return 0;
}
/*
* Write out H.262 picture data as ES or TS
*/
static int write_picture_data(WRITER output,
int as_TS,
h262_picture_p picture,
uint32_t pid)
{
int err;
if (as_TS)
{
err = write_h262_picture_as_TS(output.ts_output,picture,pid);
if (err)
{
print_err("### Error writing data as TS PES packet\n");
return 1;
}
}
else
{
err = write_h262_picture_as_ES(output.es_output,picture);
if (err)
{
print_err("### Error writing data as ES\n");
return 1;
}
}
return 0;
}
/*
* Read an H.262 picture from the given location
*
* Note that this only does the bare minimum necessary for our purposes
* here - it is *not* an adequate basis for a general "seek in H.262" mechanism
* (which is why it is here, rather than in h262.c).
*
* Returns 0 if all goes well, 1 if something goes wrong.
*/
static int read_h262_picture(h262_context_p context,
ES_offset where,
byte afd,
int verbose,
h262_picture_p *picture)
{
int err;
reverse_data_p reverse_data = NULL;
// Ensure that the H.262 context doesn't think it has any ES items in hand
// so that it will start building a picture from scratch
if (context->last_item)
free_h262_item(&context->last_item);
err = seek_ES(context->es,where);
if (err)
{
print_err("### Error seeking for H.262 picture to reverse\n");
return 1;
}
// Hmm - we don't want this call to "remember" the picture for us,
// since we've already done so. Thus we'll have to pretend that we
// don't have a reverse data context whilst we're making the call...
reverse_data = context->reverse_data;
context->reverse_data = NULL;
// But we *do* want to insist that the picture contain an AFD
context->add_fake_afd = TRUE;
context->last_afd = afd; // the value to use if the picture doesn't have one
err = get_next_h262_frame(context,verbose,TRUE,picture);
context->reverse_data = reverse_data;
if (err)
{
print_err("### Error reading H.262 picture when reversing\n");
return 1;
}
return 0;
}
/*
* Output an H.262 sequence header.
*
* - `es` is the input elementary stream
* - `output` is the stream to write to
* - if `as_TS` is true, then output as TS packets, not ES
* - if `verbose` is true, then extra information will be output
* - `seq_index` is the index of the sequence header in the `reverse_data`
* - `reverse_data` contains the list of pictures/access units to reverse.
*/
static int output_sequence_header(ES_p es,
WRITER output,
int as_TS,
int verbose,
uint16_t seq_index,
reverse_data_p reverse_data)
{
int err;
ES_offset seq_posn;
uint32_t seq_len;
byte *seq_data = NULL;
err = get_reverse_data(reverse_data,seq_index,NULL,&seq_posn,&seq_len,
NULL,NULL);
if (err)
{
fprint_err("### Error retrieving sequence header location at %d\n",
seq_index);
return 1;
}
if (verbose)
fprint_msg("Writing sequence header %2d from " OFFSET_T_FORMAT_08
"/%04d for %5d\n",
seq_index,seq_posn.infile,seq_posn.inpacket,seq_len);
err = read_ES_data(es,seq_posn,seq_len,NULL,&seq_data);
if (err)
{
fprint_err("### Error reading (sequence header) data"
" from " OFFSET_T_FORMAT "/%d for %d\n",
seq_posn.infile,seq_posn.inpacket,seq_len);
return 1;
}
err = write_packet_data(output,as_TS,seq_data,seq_len,reverse_data->pid,
reverse_data->stream_id);
free(seq_data);
if (err)
{
print_err("### Error writing (sequence header) data as"
" TS PES packet\n");
return 1;
}
return 0;
}
/*
* Output the last picture (or an earlier one) from the reverse arrays.
*
* This is expected to be used after the whole of the data stream has been
* played, so that the last picture in the reverse arrays is the last I or
* IDR picture in the data stream.
*
* - `es` is the input elementary stream
* - `output` is the stream to write to
* - if `as_TS` is true, then output as TS packets, not ES
* - if `verbose` is true, then extra information will be output
* - if `quiet` is true, then only errors will be reported
* - `offset` is the offset from the end of the array of the picture
* to output - so 0 means the last picture, 1 the picture before that,
* and so on. Sequence headers do not count for this purpose.
* - `reverse_data` is the reverse data context.
*
* Returns 0 if all went well, or 1 if something went wrong.
*/
static int output_from_reverse_data(ES_p es,
WRITER output,
int as_TS,
int verbose,
int quiet,
uint32_t offset,
reverse_data_p reverse_data)
{
int with_sequence_headers = (!reverse_data->is_h264 &&
reverse_data->output_sequence_headers);
uint32_t which = reverse_data->length - 1; // the maximum picture index
int is_h262 = !reverse_data->is_h264;