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2719ef7d1b
If the first buffer contains only headers, the sequence initialization
command fails. On CodaHx4 the buffer must be padded to at least 512
bytes, on CODA960 it seems to be enough to just repeat the sequence and
extension headers (MPEG-2) or the VOS and VO headers (MPEG-4) once for
for sequence initialization to succeed without further bitstream data.
On CodaHx4 the headers can be repeated multiple times until the 512 byte
mark is reached.
A similar issue was solved for h.264 by padding with a filler NAL in
commit 0eef89403e ("[media] coda: pad first h.264 buffer to 512
bytes").
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
88 lines
2.2 KiB
C
88 lines
2.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Coda multi-standard codec IP - MPEG-2 helper functions
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*
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* Copyright (C) 2019 Pengutronix, Philipp Zabel
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*/
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#include <linux/kernel.h>
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#include <linux/videodev2.h>
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#include "coda.h"
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int coda_mpeg2_profile(int profile_idc)
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{
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switch (profile_idc) {
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case 5:
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return V4L2_MPEG_VIDEO_MPEG2_PROFILE_SIMPLE;
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case 4:
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return V4L2_MPEG_VIDEO_MPEG2_PROFILE_MAIN;
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case 3:
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return V4L2_MPEG_VIDEO_MPEG2_PROFILE_SNR_SCALABLE;
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case 2:
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return V4L2_MPEG_VIDEO_MPEG2_PROFILE_SPATIALLY_SCALABLE;
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case 1:
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return V4L2_MPEG_VIDEO_MPEG2_PROFILE_HIGH;
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default:
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return -EINVAL;
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}
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}
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int coda_mpeg2_level(int level_idc)
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{
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switch (level_idc) {
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case 10:
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return V4L2_MPEG_VIDEO_MPEG2_LEVEL_LOW;
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case 8:
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return V4L2_MPEG_VIDEO_MPEG2_LEVEL_MAIN;
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case 6:
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return V4L2_MPEG_VIDEO_MPEG2_LEVEL_HIGH_1440;
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case 4:
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return V4L2_MPEG_VIDEO_MPEG2_LEVEL_HIGH;
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default:
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return -EINVAL;
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}
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}
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/*
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* Check if the buffer starts with the MPEG-2 sequence header (with or without
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* quantization matrix) and extension header, for example:
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*
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* 00 00 01 b3 2d 01 e0 34 08 8b a3 81
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* 10 11 11 12 12 12 13 13 13 13 14 14 14 14 14 15
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* 15 15 15 15 15 16 16 16 16 16 16 16 17 17 17 17
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* 17 17 17 17 18 18 18 19 18 18 18 19 1a 1a 1a 1a
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* 19 1b 1b 1b 1b 1b 1c 1c 1c 1c 1e 1e 1e 1f 1f 21
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* 00 00 01 b5 14 8a 00 01 00 00
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*
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* or:
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*
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* 00 00 01 b3 08 00 40 15 ff ff e0 28
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* 00 00 01 b5 14 8a 00 01 00 00
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*
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* Returns the detected header size in bytes or 0.
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*/
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u32 coda_mpeg2_parse_headers(struct coda_ctx *ctx, u8 *buf, u32 size)
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{
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static const u8 sequence_header_start[4] = { 0x00, 0x00, 0x01, 0xb3 };
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static const union {
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u8 extension_start[4];
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u8 start_code_prefix[3];
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} u = { { 0x00, 0x00, 0x01, 0xb5 } };
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if (size < 22 ||
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memcmp(buf, sequence_header_start, 4) != 0)
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return 0;
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if ((size == 22 ||
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(size >= 25 && memcmp(buf + 22, u.start_code_prefix, 3) == 0)) &&
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memcmp(buf + 12, u.extension_start, 4) == 0)
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return 22;
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if ((size == 86 ||
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(size > 89 && memcmp(buf + 86, u.start_code_prefix, 3) == 0)) &&
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memcmp(buf + 76, u.extension_start, 4) == 0)
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return 86;
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return 0;
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}
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