libavformat/mpjpegdec.c - nest-android-app/ffmpeg - Git at Google

 /*
  * Multipart JPEG format
  * Copyright (c) 2015 Luca Barbato
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */

 #include "libavutil/avstring.h"
 #include "libavutil/opt.h"

 #include "avformat.h"
 #include "internal.h"
 #include "avio_internal.h"


 typedef struct MPJPEGDemuxContext {
     const AVClass *class;
     char       *boundary;
     char       *searchstr;
     int         searchstr_len;
     int         strict_mime_boundary;
 } MPJPEGDemuxContext;


 static void trim_right(char *p)
 {
     char *end;

     if (!p || !*p)
         return;

     end = p + strlen(p);
     while (end > p && av_isspace(*(end-1)))
         *(--end) = '\0';
 }

 static int get_line(AVIOContext *pb, char *line, int line_size)
 {
     ff_get_line(pb, line, line_size);

     if (pb->error)
         return pb->error;

     if (pb->eof_reached)
         return AVERROR_EOF;

     trim_right(line);
     return 0;
 }


 static int split_tag_value(char **tag, char **value, char *line)
 {
     char *p = line;
     int  foundData = 0;

     *tag = NULL;
     *value = NULL;


     while (*p != '\0' && *p != ':') {
         if (!av_isspace(*p)) {
             foundData = 1;
         }
         p++;
     }
     if (*p != ':')
         return foundData ? AVERROR_INVALIDDATA : 0;

     *p   = '\0';
     *tag = line;
     trim_right(*tag);

     p++;

     while (av_isspace(*p))
         p++;

     *value = p;
     trim_right(*value);

     return 0;
 }

 static int parse_multipart_header(AVIOContext *pb,
                                     int* size,
                                     const char* expected_boundary,
                                     void *log_ctx);

 static int mpjpeg_read_close(AVFormatContext *s)
 {
     MPJPEGDemuxContext *mpjpeg = s->priv_data;
     av_freep(&mpjpeg->boundary);
     av_freep(&mpjpeg->searchstr);
     return 0;
 }

 static int mpjpeg_read_probe(AVProbeData *p)
 {
     AVIOContext *pb;
     int ret = 0;
     int size = 0;

     if (p->buf_size < 2 || p->buf[0] != '-' || p->buf[1] != '-')
         return 0;

     pb = avio_alloc_context(p->buf, p->buf_size, 0, NULL, NULL, NULL, NULL);
     if (!pb)
         return 0;

     ret = (parse_multipart_header(pb, &size, "--", NULL) > 0) ? AVPROBE_SCORE_MAX : 0;

     av_free(pb);

     return ret;
 }

 static int mpjpeg_read_header(AVFormatContext *s)
 {
     AVStream *st;
     char boundary[70 + 2 + 1] = {0};
     int64_t pos = avio_tell(s->pb);
     int ret;

     do {
         ret = get_line(s->pb, boundary, sizeof(boundary));
         if (ret < 0)
             return ret;
     } while (!boundary[0]);

     if (strncmp(boundary, "--", 2))
         return AVERROR_INVALIDDATA;

     st = avformat_new_stream(s, NULL);
     if (!st)
         return AVERROR(ENOMEM);

     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
     st->codec->codec_id   = AV_CODEC_ID_MJPEG;

     avpriv_set_pts_info(st, 60, 1, 25);

     avio_seek(s->pb, pos, SEEK_SET);

     return 0;
 }

 static int parse_content_length(const char *value)
 {
     long int val = strtol(value, NULL, 10);

     if (val == LONG_MIN || val == LONG_MAX)
         return AVERROR(errno);
     if (val > INT_MAX)
         return AVERROR(ERANGE);
     return val;
 }

 static int parse_multipart_header(AVIOContext *pb,
                             int* size,
                             const char* expected_boundary,
                             void *log_ctx)
 {
     char line[128];
     int found_content_type = 0;
     int ret;

     *size = -1;

     // get the CRLF as empty string
     ret = get_line(pb, line, sizeof(line));
     if (ret < 0)
         return ret;

     /* some implementation do not provide the required
      * initial CRLF (see rfc1341 7.2.1)
      */
     while (!line[0]) {
         ret = get_line(pb, line, sizeof(line));
         if (ret < 0)
             return ret;
     }

     if (!av_strstart(line, expected_boundary, NULL)) {
         if (log_ctx)
         av_log(log_ctx,
             AV_LOG_ERROR,
             "Expected boundary '%s' not found, instead found a line of %zu bytes\n",
             expected_boundary,
             strlen(line));

         return AVERROR_INVALIDDATA;
     }

     while (!pb->eof_reached) {
         char *tag, *value;

         ret = get_line(pb, line, sizeof(line));
         if (ret < 0) {
             if (ret == AVERROR_EOF)
                 break;
             return ret;
         }

         if (line[0] == '\0')
             break;

         ret = split_tag_value(&tag, &value, line);
         if (ret < 0)
             return ret;
         if (value==NULL || tag==NULL)
             break;

         if (!av_strcasecmp(tag, "Content-type")) {
             if (av_strcasecmp(value, "image/jpeg")) {
                 if (log_ctx)
                 av_log(log_ctx, AV_LOG_ERROR,
                            "Unexpected %s : %s\n",
                            tag, value);
                 return AVERROR_INVALIDDATA;
             } else
                 found_content_type = 1;
         } else if (!av_strcasecmp(tag, "Content-Length")) {
             *size = parse_content_length(value);
             if ( *size < 0 )
                 if (log_ctx)
                 av_log(log_ctx, AV_LOG_WARNING,
                            "Invalid Content-Length value : %s\n",
                            value);
         }
     }

     return found_content_type ? 0 : AVERROR_INVALIDDATA;
 }


 static char* mpjpeg_get_boundary(AVIOContext* pb)
 {
     uint8_t *mime_type = NULL;
     const char *start;
     const char *end;
     uint8_t *res = NULL;
     int     len;

     /* get MIME type, and skip to the first parameter */
     av_opt_get(pb, "mime_type", AV_OPT_SEARCH_CHILDREN, &mime_type);
     start = mime_type;
     while (start != NULL && *start != '\0') {
         start = strchr(start, ';');
         if (!start)
             break;

         start = start+1;

         while (av_isspace(*start))
             start++;

         if (!av_stristart(start, "boundary=", &start)) {
             end = strchr(start, ';');
             if (end)
                 len = end - start - 1;
             else
                 len = strlen(start);

             /* some endpoints may enclose the boundary
               in Content-Type in quotes */
             if ( len>2 && *start == '"' && start[len-1] == '"' ) {
                 start++;
                 len -= 2;
             }
             res = av_strndup(start, len);
             break;
         }
     }

     av_freep(&mime_type);
     return res;
 }


 static int mpjpeg_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     int size;
     int ret;

     MPJPEGDemuxContext *mpjpeg = s->priv_data;
     if (mpjpeg->boundary == NULL) {
         uint8_t* boundary = NULL;
         if (mpjpeg->strict_mime_boundary) {
             boundary = mpjpeg_get_boundary(s->pb);
         }
         if (boundary != NULL) {
             mpjpeg->boundary = boundary;
             mpjpeg->searchstr = av_asprintf( "\r\n%s\r\n", boundary );
         } else {
             mpjpeg->boundary = av_strdup("--");
             mpjpeg->searchstr = av_strdup("\r\n--");
         }
         if (!mpjpeg->boundary || !mpjpeg->searchstr) {
             av_freep(&mpjpeg->boundary);
             av_freep(&mpjpeg->searchstr);
             return AVERROR(ENOMEM);
         }
         mpjpeg->searchstr_len = strlen(mpjpeg->searchstr);
     }

     ret = parse_multipart_header(s->pb, &size, mpjpeg->boundary, s);


     if (ret < 0)
         return ret;

     if (size > 0) {
         /* size has been provided to us in MIME header */
         ret = av_get_packet(s->pb, pkt, size);
     } else {
         /* no size was given -- we read until the next boundary or end-of-file */
         int remaining = 0, len;

         const int read_chunk = 2048;
         av_init_packet(pkt);
         pkt->data = NULL;
         pkt->size = 0;
         pkt->pos  = avio_tell(s->pb);

         /* we may need to return as much as all we've read back to the buffer */
         ffio_ensure_seekback(s->pb, read_chunk);

         while ((ret = av_append_packet(s->pb, pkt, read_chunk - remaining)) >= 0) {
             /* scan the new data */
             char *start;

             len = ret + remaining;
             start = pkt->data + pkt->size - len;
             do {
                 if (!memcmp(start, mpjpeg->searchstr, mpjpeg->searchstr_len)) {
                     // got the boundary! rewind the stream
                     avio_seek(s->pb, -len, SEEK_CUR);
                     pkt->size -= len;
                     return pkt->size;
                 }
                 len--;
                 start++;
             } while (len >= mpjpeg->searchstr_len);
             remaining = len;
         }

         /* error or EOF occurred */
         if (ret == AVERROR_EOF) {
             ret = pkt->size > 0 ? pkt->size : AVERROR_EOF;
         } else {
             av_packet_unref(pkt);
         }
     }

     return ret;
 }

 #define OFFSET(x) offsetof(MPJPEGDemuxContext, x)

 #define DEC AV_OPT_FLAG_DECODING_PARAM
 const AVOption mpjpeg_options[] = {
     { "strict_mime_boundary",  "require MIME boundaries match", OFFSET(strict_mime_boundary), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DEC },
     { NULL }
 };


 static const AVClass mpjpeg_demuxer_class = {
     .class_name     = "MPJPEG demuxer",
     .item_name      = av_default_item_name,
     .option         = mpjpeg_options,
     .version        = LIBAVUTIL_VERSION_INT,
 };

 AVInputFormat ff_mpjpeg_demuxer = {
     .name              = "mpjpeg",
     .long_name         = NULL_IF_CONFIG_SMALL("MIME multipart JPEG"),
     .mime_type         = "multipart/x-mixed-replace",
     .extensions        = "mjpg",
     .priv_data_size    = sizeof(MPJPEGDemuxContext),
     .read_probe        = mpjpeg_read_probe,
     .read_header       = mpjpeg_read_header,
     .read_packet       = mpjpeg_read_packet,
     .read_close        = mpjpeg_read_close,
     .priv_class        = &mpjpeg_demuxer_class
 };
	/*
	* Multipart JPEG format
	* Copyright (c) 2015 Luca Barbato
	*
	* This file is part of FFmpeg.
	*
	* FFmpeg is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2.1 of the License, or (at your option) any later version.
	*
	* FFmpeg is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser General Public
	* License along with FFmpeg; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	*/

	#include "libavutil/avstring.h"
	#include "libavutil/opt.h"

	#include "avformat.h"
	#include "internal.h"
	#include "avio_internal.h"



	typedef struct MPJPEGDemuxContext {
	const AVClass *class;
	char *boundary;
	char *searchstr;
	int searchstr_len;
	int strict_mime_boundary;
	} MPJPEGDemuxContext;


	static void trim_right(char *p)
	{
	char *end;

	if (!p \|\| !*p)
	return;

	end = p + strlen(p);
	while (end > p && av_isspace(*(end-1)))
	*(--end) = '\0';
	}

	static int get_line(AVIOContext pb, char line, int line_size)
	{
	ff_get_line(pb, line, line_size);

	if (pb->error)
	return pb->error;

	if (pb->eof_reached)
	return AVERROR_EOF;

	trim_right(line);
	return 0;
	}



	static int split_tag_value(char tag, char value, char *line)
	{
	char *p = line;
	int foundData = 0;

	*tag = NULL;
	*value = NULL;


	while (p != '\0' && p != ':') {
	if (!av_isspace(*p)) {
	foundData = 1;
	}
	p++;
	}
	if (*p != ':')
	return foundData ? AVERROR_INVALIDDATA : 0;

	*p = '\0';
	*tag = line;
	trim_right(*tag);

	p++;

	while (av_isspace(*p))
	p++;

	*value = p;
	trim_right(*value);

	return 0;
	}

	static int parse_multipart_header(AVIOContext *pb,
	int* size,
	const char* expected_boundary,
	void *log_ctx);

	static int mpjpeg_read_close(AVFormatContext *s)
	{
	MPJPEGDemuxContext *mpjpeg = s->priv_data;
	av_freep(&mpjpeg->boundary);
	av_freep(&mpjpeg->searchstr);
	return 0;
	}

	static int mpjpeg_read_probe(AVProbeData *p)
	{
	AVIOContext *pb;
	int ret = 0;
	int size = 0;

	if (p->buf_size < 2 \|\| p->buf[0] != '-' \|\| p->buf[1] != '-')
	return 0;

	pb = avio_alloc_context(p->buf, p->buf_size, 0, NULL, NULL, NULL, NULL);
	if (!pb)
	return 0;

	ret = (parse_multipart_header(pb, &size, "--", NULL) > 0) ? AVPROBE_SCORE_MAX : 0;

	av_free(pb);

	return ret;
	}

	static int mpjpeg_read_header(AVFormatContext *s)
	{
	AVStream *st;
	char boundary[70 + 2 + 1] = {0};
	int64_t pos = avio_tell(s->pb);
	int ret;

	do {
	ret = get_line(s->pb, boundary, sizeof(boundary));
	if (ret < 0)
	return ret;
	} while (!boundary[0]);

	if (strncmp(boundary, "--", 2))
	return AVERROR_INVALIDDATA;

	st = avformat_new_stream(s, NULL);
	if (!st)
	return AVERROR(ENOMEM);

	st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
	st->codec->codec_id = AV_CODEC_ID_MJPEG;

	avpriv_set_pts_info(st, 60, 1, 25);

	avio_seek(s->pb, pos, SEEK_SET);

	return 0;
	}

	static int parse_content_length(const char *value)
	{
	long int val = strtol(value, NULL, 10);

	if (val == LONG_MIN \|\| val == LONG_MAX)
	return AVERROR(errno);
	if (val > INT_MAX)
	return AVERROR(ERANGE);
	return val;
	}

	static int parse_multipart_header(AVIOContext *pb,
	int* size,
	const char* expected_boundary,
	void *log_ctx)
	{
	char line[128];
	int found_content_type = 0;
	int ret;

	*size = -1;

	// get the CRLF as empty string
	ret = get_line(pb, line, sizeof(line));
	if (ret < 0)
	return ret;

	/* some implementation do not provide the required
	* initial CRLF (see rfc1341 7.2.1)
	*/
	while (!line[0]) {
	ret = get_line(pb, line, sizeof(line));
	if (ret < 0)
	return ret;
	}

	if (!av_strstart(line, expected_boundary, NULL)) {
	if (log_ctx)
	av_log(log_ctx,
	AV_LOG_ERROR,
	"Expected boundary '%s' not found, instead found a line of %zu bytes\n",
	expected_boundary,
	strlen(line));

	return AVERROR_INVALIDDATA;
	}

	while (!pb->eof_reached) {
	char tag, value;

	ret = get_line(pb, line, sizeof(line));
	if (ret < 0) {
	if (ret == AVERROR_EOF)
	break;
	return ret;
	}

	if (line[0] == '\0')
	break;

	ret = split_tag_value(&tag, &value, line);
	if (ret < 0)
	return ret;
	if (value==NULL \|\| tag==NULL)
	break;

	if (!av_strcasecmp(tag, "Content-type")) {
	if (av_strcasecmp(value, "image/jpeg")) {
	if (log_ctx)
	av_log(log_ctx, AV_LOG_ERROR,
	"Unexpected %s : %s\n",
	tag, value);
	return AVERROR_INVALIDDATA;
	} else
	found_content_type = 1;
	} else if (!av_strcasecmp(tag, "Content-Length")) {
	*size = parse_content_length(value);
	if ( *size < 0 )
	if (log_ctx)
	av_log(log_ctx, AV_LOG_WARNING,
	"Invalid Content-Length value : %s\n",
	value);
	}
	}

	return found_content_type ? 0 : AVERROR_INVALIDDATA;
	}


	static char* mpjpeg_get_boundary(AVIOContext* pb)
	{
	uint8_t *mime_type = NULL;
	const char *start;
	const char *end;
	uint8_t *res = NULL;
	int len;

	/* get MIME type, and skip to the first parameter */
	av_opt_get(pb, "mime_type", AV_OPT_SEARCH_CHILDREN, &mime_type);
	start = mime_type;
	while (start != NULL && *start != '\0') {
	start = strchr(start, ';');
	if (!start)
	break;

	start = start+1;

	while (av_isspace(*start))
	start++;

	if (!av_stristart(start, "boundary=", &start)) {
	end = strchr(start, ';');
	if (end)
	len = end - start - 1;
	else
	len = strlen(start);

	/* some endpoints may enclose the boundary
	in Content-Type in quotes */
	if ( len>2 && *start == '"' && start[len-1] == '"' ) {
	start++;
	len -= 2;
	}
	res = av_strndup(start, len);
	break;
	}
	}

	av_freep(&mime_type);
	return res;
	}


	static int mpjpeg_read_packet(AVFormatContext s, AVPacket pkt)
	{
	int size;
	int ret;

	MPJPEGDemuxContext *mpjpeg = s->priv_data;
	if (mpjpeg->boundary == NULL) {
	uint8_t* boundary = NULL;
	if (mpjpeg->strict_mime_boundary) {
	boundary = mpjpeg_get_boundary(s->pb);
	}
	if (boundary != NULL) {
	mpjpeg->boundary = boundary;
	mpjpeg->searchstr = av_asprintf( "\r\n%s\r\n", boundary );
	} else {
	mpjpeg->boundary = av_strdup("--");
	mpjpeg->searchstr = av_strdup("\r\n--");
	}
	if (!mpjpeg->boundary \|\| !mpjpeg->searchstr) {
	av_freep(&mpjpeg->boundary);
	av_freep(&mpjpeg->searchstr);
	return AVERROR(ENOMEM);
	}
	mpjpeg->searchstr_len = strlen(mpjpeg->searchstr);
	}

	ret = parse_multipart_header(s->pb, &size, mpjpeg->boundary, s);


	if (ret < 0)
	return ret;

	if (size > 0) {
	/* size has been provided to us in MIME header */
	ret = av_get_packet(s->pb, pkt, size);
	} else {
	/* no size was given -- we read until the next boundary or end-of-file */
	int remaining = 0, len;

	const int read_chunk = 2048;
	av_init_packet(pkt);
	pkt->data = NULL;
	pkt->size = 0;
	pkt->pos = avio_tell(s->pb);

	/* we may need to return as much as all we've read back to the buffer */
	ffio_ensure_seekback(s->pb, read_chunk);

	while ((ret = av_append_packet(s->pb, pkt, read_chunk - remaining)) >= 0) {
	/* scan the new data */
	char *start;

	len = ret + remaining;
	start = pkt->data + pkt->size - len;
	do {
	if (!memcmp(start, mpjpeg->searchstr, mpjpeg->searchstr_len)) {
	// got the boundary! rewind the stream
	avio_seek(s->pb, -len, SEEK_CUR);
	pkt->size -= len;
	return pkt->size;
	}
	len--;
	start++;
	} while (len >= mpjpeg->searchstr_len);
	remaining = len;
	}

	/* error or EOF occurred */
	if (ret == AVERROR_EOF) {
	ret = pkt->size > 0 ? pkt->size : AVERROR_EOF;
	} else {
	av_packet_unref(pkt);
	}
	}

	return ret;
	}

	#define OFFSET(x) offsetof(MPJPEGDemuxContext, x)

	#define DEC AV_OPT_FLAG_DECODING_PARAM
	const AVOption mpjpeg_options[] = {
	{ "strict_mime_boundary", "require MIME boundaries match", OFFSET(strict_mime_boundary), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DEC },
	{ NULL }
	};


	static const AVClass mpjpeg_demuxer_class = {
	.class_name = "MPJPEG demuxer",
	.item_name = av_default_item_name,
	.option = mpjpeg_options,
	.version = LIBAVUTIL_VERSION_INT,
	};

	AVInputFormat ff_mpjpeg_demuxer = {
	.name = "mpjpeg",
	.long_name = NULL_IF_CONFIG_SMALL("MIME multipart JPEG"),
	.mime_type = "multipart/x-mixed-replace",
	.extensions = "mjpg",
	.priv_data_size = sizeof(MPJPEGDemuxContext),
	.read_probe = mpjpeg_read_probe,
	.read_header = mpjpeg_read_header,
	.read_packet = mpjpeg_read_packet,
	.read_close = mpjpeg_read_close,
	.priv_class = &mpjpeg_demuxer_class
	};