/src/ffmpeg/libavcodec/parser.c

Source
/*
 * Audio and Video frame extraction
 * Copyright (c) 2003 Fabrice Bellard
 * Copyright (c) 2003 Michael Niedermayer
 *
 * 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 <inttypes.h>
#include <stdint.h>
#include <string.h>

#include "libavutil/attributes.h"
#include "libavutil/avassert.h"
#include "libavutil/mem.h"

#include "codec_desc.h"
#include "parser.h"
#include "parser_internal.h"

av_cold AVCodecParserContext *av_parser_init(enum AVCodecID codec_id)
{
    AVCodecParserContext *s = NULL;
    const AVCodecParser *parser;
    const FFCodecParser *ffparser;
    void *i = 0;
    int ret;

    if (codec_id == AV_CODEC_ID_NONE)
        return NULL;

    while ((parser = av_parser_iterate(&i))) {
        if (parser->codec_ids[0] == codec_id ||
            parser->codec_ids[1] == codec_id ||
            parser->codec_ids[2] == codec_id ||
            parser->codec_ids[3] == codec_id ||
            parser->codec_ids[4] == codec_id ||
            parser->codec_ids[5] == codec_id ||
            parser->codec_ids[6] == codec_id)
            goto found;
    }
    return NULL;

found:
    ffparser = ffcodecparser(parser);
    s = av_mallocz(sizeof(AVCodecParserContext));
    if (!s)
        goto err_out;
    s->parser = parser;
    s->priv_data = av_mallocz(ffparser->priv_data_size);
    if (!s->priv_data)
        goto err_out;
    s->fetch_timestamp=1;
    s->pict_type = AV_PICTURE_TYPE_I;
    if (ffparser->init) {
        ret = ffparser->init(s);
        if (ret != 0)
            goto err_out;
    }
    s->key_frame            = -1;
    s->dts_sync_point       = INT_MIN;
    s->dts_ref_dts_delta    = INT_MIN;
    s->pts_dts_delta        = INT_MIN;
    s->format               = -1;

    return s;

err_out:
    if (s)
        av_freep(&s->priv_data);
    av_free(s);
    return NULL;
}

void ff_fetch_timestamp(AVCodecParserContext *s, int off, int remove, int fuzzy)
{
    int i;

    if (!fuzzy) {
        s->dts    =
        s->pts    = AV_NOPTS_VALUE;
        s->pos    = -1;
        s->offset = 0;
    }
    for (i = 0; i < AV_PARSER_PTS_NB; i++) {
        if (s->cur_offset + off >= s->cur_frame_offset[i] &&
            (s->frame_offset < s->cur_frame_offset[i] ||
             (!s->frame_offset && !s->next_frame_offset)) && // first field/frame
            // check disabled since MPEG-TS does not send complete PES packets
            /*s->next_frame_offset + off <*/  s->cur_frame_end[i]){

            if (!fuzzy || s->cur_frame_dts[i] != AV_NOPTS_VALUE) {
                s->dts    = s->cur_frame_dts[i];
                s->pts    = s->cur_frame_pts[i];
                s->pos    = s->cur_frame_pos[i];
                s->offset = s->next_frame_offset - s->cur_frame_offset[i];
            }
            if (remove)
                s->cur_frame_offset[i] = INT64_MAX;
            if (s->cur_offset + off < s->cur_frame_end[i])
                break;
        }
    }
}

int av_parser_parse2(AVCodecParserContext *s, AVCodecContext *avctx,
                     uint8_t **poutbuf, int *poutbuf_size,
                     const uint8_t *buf, int buf_size,
                     int64_t pts, int64_t dts, int64_t pos)
{
    const AVCodecDescriptor *desc;
    int index, i;
    uint8_t dummy_buf[AV_INPUT_BUFFER_PADDING_SIZE];

    av_assert1(avctx->codec_id != AV_CODEC_ID_NONE);

    /* Parsers only work for the specified codec ids. */
    av_assert1(avctx->codec_id == s->parser->codec_ids[0] ||
               avctx->codec_id == s->parser->codec_ids[1] ||
               avctx->codec_id == s->parser->codec_ids[2] ||
               avctx->codec_id == s->parser->codec_ids[3] ||
               avctx->codec_id == s->parser->codec_ids[4] ||
               avctx->codec_id == s->parser->codec_ids[5] ||
               avctx->codec_id == s->parser->codec_ids[6]);

    desc = avcodec_descriptor_get(avctx->codec_id);

    if (!(s->flags & PARSER_FLAG_FETCHED_OFFSET)) {
        s->next_frame_offset =
        s->cur_offset        = pos;
        s->flags            |= PARSER_FLAG_FETCHED_OFFSET;
    }

    if (buf_size == 0) {
        /* padding is always necessary even if EOF, so we add it here */
        memset(dummy_buf, 0, sizeof(dummy_buf));
        buf = dummy_buf;
    } else if (s->cur_offset + buf_size != s->cur_frame_end[s->cur_frame_start_index]) { /* skip remainder packets */
        /* add a new packet descriptor */
        i = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1);
        s->cur_frame_start_index = i;
        s->cur_frame_offset[i]   = s->cur_offset;
        s->cur_frame_end[i]      = s->cur_offset + buf_size;
        s->cur_frame_pts[i]      = pts;
        s->cur_frame_dts[i]      = dts;
        s->cur_frame_pos[i]      = pos;
    }

    if (s->fetch_timestamp) {
        s->fetch_timestamp = 0;
        s->last_pts        = s->pts;
        s->last_dts        = s->dts;
        s->last_pos        = s->pos;
        ff_fetch_timestamp(s, 0, 0, 0);
    }
    /* WARNING: the returned index can be negative */
    index = ffcodecparser(s->parser)->parse(s, avctx, (const uint8_t **) poutbuf,
                                            poutbuf_size, buf, buf_size);
    av_assert0(index > -0x20000000); // The API does not allow returning AVERROR codes
#define FILL(name) if(s->name > 0 && avctx->name <= 0) avctx->name = s->name
    if (avctx->codec_type == AVMEDIA_TYPE_VIDEO) {
        FILL(field_order);
        FILL(coded_width);
        FILL(coded_height);
        FILL(width);
        FILL(height);
        if (desc && (desc->props & AV_CODEC_PROP_ENHANCEMENT) &&
            s->format >= 0 && avctx->pix_fmt < 0) avctx->pix_fmt = s->format;
    }

    /* update the file pointer */
    if (*poutbuf_size) {
        /* fill the data for the current frame */
        s->frame_offset = s->next_frame_offset;

        /* offset of the next frame */
        s->next_frame_offset = s->cur_offset + index;
        s->fetch_timestamp   = 1;
    } else {
        /* Don't return a pointer to dummy_buf. */
        *poutbuf = NULL;
    }
    if (index < 0)
        index = 0;
    s->cur_offset += index;
    return index;
}

av_cold void av_parser_close(AVCodecParserContext *s)
{
    if (s) {
        if (ffcodecparser(s->parser)->close)
            ffcodecparser(s->parser)->close(s);
        av_freep(&s->priv_data);
        av_free(s);
    }
}

int ff_combine_frame(ParseContext *pc, int next,
                     const uint8_t **buf, int *buf_size)
{
    if (pc->overread) {
        ff_dlog(NULL, "overread %d, state:%"PRIX32" next:%d index:%d o_index:%d\n",
                pc->overread, pc->state, next, pc->index, pc->overread_index);
        ff_dlog(NULL, "%X %X %X %X\n",
                (*buf)[0], (*buf)[1], (*buf)[2], (*buf)[3]);
    }

    /* Copy overread bytes from last frame into buffer. */
    for (; pc->overread > 0; pc->overread--)
        pc->buffer[pc->index++] = pc->buffer[pc->overread_index++];

    if (next > *buf_size)
        return AVERROR(EINVAL);

    /* flush remaining if EOF */
    if (!*buf_size && next == END_NOT_FOUND)
        next = 0;

    pc->last_index = pc->index;

    /* copy into buffer end return */
    if (next == END_NOT_FOUND) {
        void *new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size,
                                           *buf_size + pc->index +
                                           AV_INPUT_BUFFER_PADDING_SIZE);

        if (!new_buffer) {
            av_log(NULL, AV_LOG_ERROR, "Failed to reallocate parser buffer to %d\n", *buf_size + pc->index + AV_INPUT_BUFFER_PADDING_SIZE);
            pc->index = 0;
            return AVERROR(ENOMEM);
        }
        pc->buffer = new_buffer;
        memcpy(&pc->buffer[pc->index], *buf, *buf_size);
        memset(&pc->buffer[pc->index + *buf_size], 0, AV_INPUT_BUFFER_PADDING_SIZE);
        pc->index += *buf_size;
        return -1;
    }

    av_assert0(next >= 0 || pc->buffer);

    *buf_size          =
    pc->overread_index = pc->index + next;

    /* append to buffer */
    if (pc->index) {
        void *new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size,
                                           next + pc->index +
                                           AV_INPUT_BUFFER_PADDING_SIZE);
        if (!new_buffer) {
            av_log(NULL, AV_LOG_ERROR, "Failed to reallocate parser buffer to %d\n", next + pc->index + AV_INPUT_BUFFER_PADDING_SIZE);
            *buf_size =
            pc->overread_index =
            pc->index = 0;
            return AVERROR(ENOMEM);
        }
        pc->buffer = new_buffer;
        if (next > -AV_INPUT_BUFFER_PADDING_SIZE)
            memcpy(&pc->buffer[pc->index], *buf,
                   next + AV_INPUT_BUFFER_PADDING_SIZE);
        pc->index = 0;
        *buf      = pc->buffer;
    }

    if (next < -8) {
        pc->overread += -8 - next;
        next = -8;
    }
    /* store overread bytes */
    for (; next < 0; next++) {
        pc->state   = pc->state   << 8 | pc->buffer[pc->last_index + next];
        pc->state64 = pc->state64 << 8 | pc->buffer[pc->last_index + next];
        pc->overread++;
    }

    if (pc->overread) {
        ff_dlog(NULL, "overread %d, state:%"PRIX32" next:%d index:%d o_index:%d\n",
                pc->overread, pc->state, next, pc->index, pc->overread_index);
        ff_dlog(NULL, "%X %X %X %X\n",
                (*buf)[0], (*buf)[1], (*buf)[2], (*buf)[3]);
    }

    return 0;
}

av_cold void ff_parse_close(AVCodecParserContext *s)
{
    ParseContext *pc = s->priv_data;

    av_freep(&pc->buffer);
}

Coverage Report

Created: 2026-07-15 07:31

Line	Count	Source
1		/*
2		* Audio and Video frame extraction
3		* Copyright (c) 2003 Fabrice Bellard
4		* Copyright (c) 2003 Michael Niedermayer
5		*
6		* This file is part of FFmpeg.
7		*
8		* FFmpeg is free software; you can redistribute it and/or
9		* modify it under the terms of the GNU Lesser General Public
10		* License as published by the Free Software Foundation; either
11		* version 2.1 of the License, or (at your option) any later version.
12		*
13		* FFmpeg is distributed in the hope that it will be useful,
14		* but WITHOUT ANY WARRANTY; without even the implied warranty of
15		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16		* Lesser General Public License for more details.
17		*
18		* You should have received a copy of the GNU Lesser General Public
19		* License along with FFmpeg; if not, write to the Free Software
20		* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21		*/
22
23		#include <inttypes.h>
24		#include <stdint.h>
25		#include <string.h>
26
27		#include "libavutil/attributes.h"
28		#include "libavutil/avassert.h"
29		#include "libavutil/mem.h"
30
31		#include "codec_desc.h"
32		#include "parser.h"
33		#include "parser_internal.h"
34
35		av_cold AVCodecParserContext *av_parser_init(enum AVCodecID codec_id)
36	0	{
37	0	AVCodecParserContext *s = NULL;
38	0	const AVCodecParser *parser;
39	0	const FFCodecParser *ffparser;
40	0	void *i = 0;
41	0	int ret;
42
43	0	if (codec_id == AV_CODEC_ID_NONE)
44	0	return NULL;
45
46	0	while ((parser = av_parser_iterate(&i))) {
47	0	if (parser->codec_ids[0] == codec_id \|\|
48	0	parser->codec_ids[1] == codec_id \|\|
49	0	parser->codec_ids[2] == codec_id \|\|
50	0	parser->codec_ids[3] == codec_id \|\|
51	0	parser->codec_ids[4] == codec_id \|\|
52	0	parser->codec_ids[5] == codec_id \|\|
53	0	parser->codec_ids[6] == codec_id)
54	0	goto found;
55	0	}
56	0	return NULL;
57
58	0	found:
59	0	ffparser = ffcodecparser(parser);
60	0	s = av_mallocz(sizeof(AVCodecParserContext));
61	0	if (!s)
62	0	goto err_out;
63	0	s->parser = parser;
64	0	s->priv_data = av_mallocz(ffparser->priv_data_size);
65	0	if (!s->priv_data)
66	0	goto err_out;
67	0	s->fetch_timestamp=1;
68	0	s->pict_type = AV_PICTURE_TYPE_I;
69	0	if (ffparser->init) {
70	0	ret = ffparser->init(s);
71	0	if (ret != 0)
72	0	goto err_out;
73	0	}
74	0	s->key_frame = -1;
75	0	s->dts_sync_point = INT_MIN;
76	0	s->dts_ref_dts_delta = INT_MIN;
77	0	s->pts_dts_delta = INT_MIN;
78	0	s->format = -1;
79
80	0	return s;
81
82	0	err_out:
83	0	if (s)
84	0	av_freep(&s->priv_data);
85	0	av_free(s);
86	0	return NULL;
87	0	}
88
89		void ff_fetch_timestamp(AVCodecParserContext *s, int off, int remove, int fuzzy)
90	0	{
91	0	int i;
92
93	0	if (!fuzzy) {
94	0	s->dts =
95	0	s->pts = AV_NOPTS_VALUE;
96	0	s->pos = -1;
97	0	s->offset = 0;
98	0	}
99	0	for (i = 0; i < AV_PARSER_PTS_NB; i++) {
100	0	if (s->cur_offset + off >= s->cur_frame_offset[i] &&
101	0	(s->frame_offset < s->cur_frame_offset[i] \|\|
102	0	(!s->frame_offset && !s->next_frame_offset)) && // first field/frame
103		// check disabled since MPEG-TS does not send complete PES packets
104	0	/s->next_frame_offset + off </ s->cur_frame_end[i]){
105
106	0	if (!fuzzy \|\| s->cur_frame_dts[i] != AV_NOPTS_VALUE) {
107	0	s->dts = s->cur_frame_dts[i];
108	0	s->pts = s->cur_frame_pts[i];
109	0	s->pos = s->cur_frame_pos[i];
110	0	s->offset = s->next_frame_offset - s->cur_frame_offset[i];
111	0	}
112	0	if (remove)
113	0	s->cur_frame_offset[i] = INT64_MAX;
114	0	if (s->cur_offset + off < s->cur_frame_end[i])
115	0	break;
116	0	}
117	0	}
118	0	}
119
120		int av_parser_parse2(AVCodecParserContext s, AVCodecContext avctx,
121		uint8_t *poutbuf, int poutbuf_size,
122		const uint8_t *buf, int buf_size,
123		int64_t pts, int64_t dts, int64_t pos)
124	0	{
125	0	const AVCodecDescriptor *desc;
126	0	int index, i;
127	0	uint8_t dummy_buf[AV_INPUT_BUFFER_PADDING_SIZE];
128
129	0	av_assert1(avctx->codec_id != AV_CODEC_ID_NONE);
130
131		/* Parsers only work for the specified codec ids. */
132	0	av_assert1(avctx->codec_id == s->parser->codec_ids[0] \|\|
133	0	avctx->codec_id == s->parser->codec_ids[1] \|\|
134	0	avctx->codec_id == s->parser->codec_ids[2] \|\|
135	0	avctx->codec_id == s->parser->codec_ids[3] \|\|
136	0	avctx->codec_id == s->parser->codec_ids[4] \|\|
137	0	avctx->codec_id == s->parser->codec_ids[5] \|\|
138	0	avctx->codec_id == s->parser->codec_ids[6]);
139
140	0	desc = avcodec_descriptor_get(avctx->codec_id);
141
142	0	if (!(s->flags & PARSER_FLAG_FETCHED_OFFSET)) {
143	0	s->next_frame_offset =
144	0	s->cur_offset = pos;
145	0	s->flags \|= PARSER_FLAG_FETCHED_OFFSET;
146	0	}
147
148	0	if (buf_size == 0) {
149		/* padding is always necessary even if EOF, so we add it here */
150	0	memset(dummy_buf, 0, sizeof(dummy_buf));
151	0	buf = dummy_buf;
152	0	} else if (s->cur_offset + buf_size != s->cur_frame_end[s->cur_frame_start_index]) { /* skip remainder packets */
153		/* add a new packet descriptor */
154	0	i = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1);
155	0	s->cur_frame_start_index = i;
156	0	s->cur_frame_offset[i] = s->cur_offset;
157	0	s->cur_frame_end[i] = s->cur_offset + buf_size;
158	0	s->cur_frame_pts[i] = pts;
159	0	s->cur_frame_dts[i] = dts;
160	0	s->cur_frame_pos[i] = pos;
161	0	}
162
163	0	if (s->fetch_timestamp) {
164	0	s->fetch_timestamp = 0;
165	0	s->last_pts = s->pts;
166	0	s->last_dts = s->dts;
167	0	s->last_pos = s->pos;
168	0	ff_fetch_timestamp(s, 0, 0, 0);
169	0	}
170		/* WARNING: the returned index can be negative */
171	0	index = ffcodecparser(s->parser)->parse(s, avctx, (const uint8_t **) poutbuf,
172	0	poutbuf_size, buf, buf_size);
173	0	av_assert0(index > -0x20000000); // The API does not allow returning AVERROR codes
174	0	#define FILL(name) if(s->name > 0 && avctx->name <= 0) avctx->name = s->name
175	0	if (avctx->codec_type == AVMEDIA_TYPE_VIDEO) {
176	0	FILL(field_order);
177	0	FILL(coded_width);
178	0	FILL(coded_height);
179	0	FILL(width);
180	0	FILL(height);
181	0	if (desc && (desc->props & AV_CODEC_PROP_ENHANCEMENT) &&
182	0	s->format >= 0 && avctx->pix_fmt < 0) avctx->pix_fmt = s->format;
183	0	}
184
185		/* update the file pointer */
186	0	if (*poutbuf_size) {
187		/* fill the data for the current frame */
188	0	s->frame_offset = s->next_frame_offset;
189
190		/* offset of the next frame */
191	0	s->next_frame_offset = s->cur_offset + index;
192	0	s->fetch_timestamp = 1;
193	0	} else {
194		/* Don't return a pointer to dummy_buf. */
195	0	*poutbuf = NULL;
196	0	}
197	0	if (index < 0)
198	0	index = 0;
199	0	s->cur_offset += index;
200	0	return index;
201	0	}
202
203		av_cold void av_parser_close(AVCodecParserContext *s)
204	0	{
205	0	if (s) {
206	0	if (ffcodecparser(s->parser)->close)
207	0	ffcodecparser(s->parser)->close(s);
208	0	av_freep(&s->priv_data);
209	0	av_free(s);
210	0	}
211	0	}
212
213		int ff_combine_frame(ParseContext *pc, int next,
214		const uint8_t *buf, int buf_size)
215	0	{
216	0	if (pc->overread) {
217	0	ff_dlog(NULL, "overread %d, state:%"PRIX32" next:%d index:%d o_index:%d\n",
218	0	pc->overread, pc->state, next, pc->index, pc->overread_index);
219	0	ff_dlog(NULL, "%X %X %X %X\n",
220	0	(buf)[0], (buf)[1], (buf)[2], (buf)[3]);
221	0	}
222
223		/* Copy overread bytes from last frame into buffer. */
224	0	for (; pc->overread > 0; pc->overread--)
225	0	pc->buffer[pc->index++] = pc->buffer[pc->overread_index++];
226
227	0	if (next > *buf_size)
228	0	return AVERROR(EINVAL);
229
230		/* flush remaining if EOF */
231	0	if (!*buf_size && next == END_NOT_FOUND)
232	0	next = 0;
233
234	0	pc->last_index = pc->index;
235
236		/* copy into buffer end return */
237	0	if (next == END_NOT_FOUND) {
238	0	void *new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size,
239	0	*buf_size + pc->index +
240	0	AV_INPUT_BUFFER_PADDING_SIZE);
241
242	0	if (!new_buffer) {
243	0	av_log(NULL, AV_LOG_ERROR, "Failed to reallocate parser buffer to %d\n", *buf_size + pc->index + AV_INPUT_BUFFER_PADDING_SIZE);
244	0	pc->index = 0;
245	0	return AVERROR(ENOMEM);
246	0	}
247	0	pc->buffer = new_buffer;
248	0	memcpy(&pc->buffer[pc->index], buf, buf_size);
249	0	memset(&pc->buffer[pc->index + *buf_size], 0, AV_INPUT_BUFFER_PADDING_SIZE);
250	0	pc->index += *buf_size;
251	0	return -1;
252	0	}
253
254	0	av_assert0(next >= 0 \|\| pc->buffer);
255
256	0	*buf_size =
257	0	pc->overread_index = pc->index + next;
258
259		/* append to buffer */
260	0	if (pc->index) {
261	0	void *new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size,
262	0	next + pc->index +
263	0	AV_INPUT_BUFFER_PADDING_SIZE);
264	0	if (!new_buffer) {
265	0	av_log(NULL, AV_LOG_ERROR, "Failed to reallocate parser buffer to %d\n", next + pc->index + AV_INPUT_BUFFER_PADDING_SIZE);
266	0	*buf_size =
267	0	pc->overread_index =
268	0	pc->index = 0;
269	0	return AVERROR(ENOMEM);
270	0	}
271	0	pc->buffer = new_buffer;
272	0	if (next > -AV_INPUT_BUFFER_PADDING_SIZE)
273	0	memcpy(&pc->buffer[pc->index], *buf,
274	0	next + AV_INPUT_BUFFER_PADDING_SIZE);
275	0	pc->index = 0;
276	0	*buf = pc->buffer;
277	0	}
278
279	0	if (next < -8) {
280	0	pc->overread += -8 - next;
281	0	next = -8;
282	0	}
283		/* store overread bytes */
284	0	for (; next < 0; next++) {
285	0	pc->state = pc->state << 8 \| pc->buffer[pc->last_index + next];
286	0	pc->state64 = pc->state64 << 8 \| pc->buffer[pc->last_index + next];
287	0	pc->overread++;
288	0	}
289
290	0	if (pc->overread) {
291	0	ff_dlog(NULL, "overread %d, state:%"PRIX32" next:%d index:%d o_index:%d\n",
292	0	pc->overread, pc->state, next, pc->index, pc->overread_index);
293	0	ff_dlog(NULL, "%X %X %X %X\n",
294	0	(buf)[0], (buf)[1], (buf)[2], (buf)[3]);
295	0	}
296
297	0	return 0;
298	0	}
299
300		av_cold void ff_parse_close(AVCodecParserContext *s)
301	0	{
302	0	ParseContext *pc = s->priv_data;
303
304	0	av_freep(&pc->buffer);
305	0	}